File transfer system

ABSTRACT

A file authentication requesting device that stores a computer program for requesting authentication of files in digital systems, the device comprises a confirmation request system that generates a request for a confirmation receipt from a third party authenticator authenticating the attributes of a file; a transferring system that transfers attributes of at least one file to be authenticated to the third party authenticator from the device that requested the confirmation; and a receiving system that receives the confirmation receipt comprising authenticated file attributes, after authentication by the third party authenticator; wherein, at least one file authentication is received from the third party authenticator. Corresponding processing devices, media, systems and methods are also provided.

CROSS REFERENCES TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.13/37,636, filed Oct. 24, 2011, entitled “Method and Apparatus for DataFile Transfer Using Destination Linked Directories,” which is acontinuation of U.S. patent application Ser. No. 12/661,726, filed Mar.22, 2010, entitled “Selective Acceptance of Electronic Messages inCommunication Systems,” which is now U.S. Pat. No. 8,046,825, issuedOct. 25, 2011, which is a continuation of U.S. patent application Ser.No. 12/384,736, filed Apr. 7, 2009, entitled “File Transfer System forDirect Transfer Between Computers,” which is now U.S. Pat. No.7,810,144, issued Oct. 5, 2010, and which is a continuation of U.S.patent application Ser. No. 10/657,221, filed Sep. 9, 2003, entitled“File Transfer System for Direct Transfer Between Computers,” which isnow U.S. Pat. No. 7,536,554, issued May 19, 2009, and which is acontinuation of U.S. patent application Ser. No. 10/167,697, filed Jun.13, 2002, entitled “File Transfer System,” which is now U.S. Pat. No.7,263,528, issued Aug. 28, 2007, which is a continuation of U.S. patentapplication Ser. No. 09/694,472, entitled “Methods and Apparatus forSecure Electronic, Certified, Restricted Delivery Mail Systems,” filedOct. 24, 2000, which is now U.S. Pat. No. 5,442,571, issued Aug. 27,2002; which is a continuation of U.S. patent application Ser. No.09/190,219, entitled “File Transfer System Using Dynamically AssignedPorts,” filed Nov. 13, 1998, which is now U.S. Pat. No. 6,219,669,issued Apr. 17, 2001; the disclosures of which, including appendicesthereof, are expressly incorporated herein by reference in theirentireties. This application also claims the benefit of U.S. ProvisionalPatent Application No. 60/065,533, in the names of Maurice Haff et al.,entitled “File Transfer System For Direct Transfer Between Computers,”filed on Nov. 13, 1997; U.S. Provisional Patent Application No.60/085,427, in the names of Maurice Haff et al., entitled “File TransferSystem,” filed on May 14,1998; and U.S. Provisional Application No.60/100,962, in the names of Maurice Haff et al., entitled “File TransferSystem,” filed Sep. 17, 1998; the disclosures of which, includingappendices thereof, are expressly incorporated herein by reference intheir entireties.

A portion of the disclosure of this patent document contains materialthat is subject to copyright protection. The copyright owner has noobjection to the facsimile reproduction by anyone of the patent documentor the patent disclosure, as it appears in the Patent and TrademarkOffice patent file records, but otherwise reserves all copyright rightswhatsoever.

REFERENCE TO COMPUTER PROGRAM LISTING APPENDICES

Computer program listing appendices on compact disc-recordable (CD-R),containing Appendices A-D that corresponds to the program listingsdiscussed below, are filed herewith, in accordance with 37 CFR 1.52(e).These computer program listing appendices are incorporated herein byreference in their entirety, in accordance with 37 CFR 1.77(b)(4). Thebelow referenced files were created on Oct. 24, 2011 to correspond toAppendices A-D, as originally submitted on CD-R in preceding applicationSer. No. 12/681,726 and on microfiche in preceding application Ser. Nos.10/657,221, 10/167,697, 09/694,472, and 09/190,219. The files on CD-Rare identified as follows:

Name Size Type Appendix_A.txt 462,201 bytes Text Document Appendix_B.txt211,699 bytes Text Document Appendix_C.txt  73,665 bytes Text DocumentAppendix_D.txt  42,587 bytes Text Document

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to transferring computer fileselectronically from am location to another, and more particularly toelectronic transfer of computer files directly between two or morecomputers or computing devices.

2. Background Information

Expedited delivery of documents has for generations been of greatconcern to people and of great importance to their business interests.Methods of effecting expedited document delivery have progressed toinclude same clay/next day physical delivery using international anddomestic airways and roadways, as well as electronic delivery usinginterconnected networks of computers and telecommunications equipment,worldwide. Complex logistics systems have been erected by bothgovernment and commercial enterprises to effect relatively securephysical delivery of documents from the sender to the recipient.Examples include overnight express mail delivery offered by the U.S.Postal Service and express delivery service provided by privatecompanies such as Federal Express, United Parcel Service, end DHL.Charges for delivery services rendered ere typically on fixed fee basis(per delivery), with payment made at the time the service is performed,or made via a pre arranged account with the service provider or a thirdparty credit provider (e.g. VISA or Master Card).

The complexity of these systems and the physical resources mobilized tosupport the expedited transfer service are relatively costly, with thecosts being passed on to the service user Extensive interconnectednetworks of computers and telecommunications equipped have been erectedwith the intent to lower the cost of communication, as well as tofurther expedite the transfer of information between sender andrecipient. To an extent, the evolution from physical delivery toelectronic delivery of documents has been successful as evidenced by thegrowth in the use of personal computers (PCs), the Internet and privateintranets and extranets, albeit at the expense of the relative securityof the document transfer. Examples of electronic transfer mechanisms inuse across computer networks include electronic mail (e-mail) and filetransfer protocol (FTP), both widely employed on the Internet. Examplesof electronic transfer mechanisms in use across the public switchedtelephone network. (PSTN) include facsimile transmissions, as well asfile transfers using modem's and various embodiments of computerprograms enabling data communications between computers.

Hybrid systems are also employed to provide remote access to filesstored on network servers. These hybrid systems typically employspecialized communications servers connected on a local area network andinterconnected to a counterpart communications server on another localarea network through a public network such as the Internet.Alternatively, a remote PC may be permitted to login to a communicationsserver using a dial-up connection through file PSTN. Often referred toas “Virtual private networks” or VPNs, these hybrid systems typicallyemploy encrypting techniques to create relatively secure data packetsfor transmission through client-server connections across publicnetworks. An example of a VPN product is Alta Vista, a software productavailable from Digital Equipment Corporation.

The approaches, as embodied in the physical and the electronic documentdelivery systems in use today, exhibit a number of shortcomings. Whilebeing relatively secure, slower express mall and delivery services aremore costly to the sender than more immediate delivery electronicalternatives. With electronic transfers across networks, a moreimmediate delivery of documents, data files, images, and drawings can beaccomplished. However, these methods generally employ intermediarycomputers in the form of e-mail servers, FTP servers, or Web servers.These intermediary computers reduce the relative security and timelinessof the transfers effected because neither the sender nor the recipientcontrols the intermediary server. Moreover, the intermediary serversthemselves require significant administration and usually require loginprocedures and passwords in an attempt to overcome security issues,albeit at the expense of user convenience and system complexity.Further, these intermediary computers represent concentrated points ofpossible failure, as well as communication “bottlenecks” that setcapacity limits for the collective number and size of files transferred.

Examples of an approach employing e-mail servers are cc:Mail availablefrom Lotus Development Company, and Microsoft Mall available fromMicrosoft Corporation. An example of a system employing FTP-servers andWeb-servers for IP networks is Netscape Navigator available fromNetscape Communications Corporation. Each of these systems requiresintermediary computers that function as servers to store text messagesor document files for later retrieval by the intended recipient. All ofthese systems require user login to a server and downloading of files.Thus, direct transfer of a specific file from a sending PC to a specificrecipient at a receiving PC is not enabled by these systems, nor is thesimultaneous exchange of files between multiple computers.

A variation of the e-mail concept is manifested in a recently introducedfile transfer service called “e-Parcel” available over the Internet fromMitsubishi America. “e-Parcel” is a pay subscription service employingclient-server connections through the Internet. A similar system called“NetDox” is available from NetDox, Inc. Both of these products employclient software to provide automatic login to a mediating server thatforwards a transferred file to a registered recipient when the recipientlogs in to the mediating server. E-mail addresses are used to createunique identifiers for each registered user for file routing and billingpurposes. However direct transfer of a file from the sender to therecipient without login to the forwarding server is not possible inserver-based mediated systems such as e-Parcel or NetDox. Anotherdrawback of server-based systems is that they are capacity limited interms of the number of file transmissions that can be processedsimultaneously, and the magnitude of the files that can be collectivelystored during any given time period. Server capacity must be increasedproportionally, at significant cost, as the number of users and systemuse increases. Another limitation of store and forward (mediatedtransfer) servers is that concentrators of transmitted files representsa system-level point of failure that increases both security andreliability risks.

In any document delivery system, physical or electronic, a manageablemethod of obtaining payment for the services rendered to the user is acritical element for success. In physical delivery systems for expeditedservice, payments are often made for charges to a hilling accountaccumulated monthly, with the account numbers being recorded on an“airbill” that accompanies the document package. A record of thetransaction must be captured, usually by a manual process, and enteredinto a computer accounting system. The United States Postal Service(USPS), as well as other national postal systems, have long offeredmechanical postage meters for placing “metered stamps” on envelopes tobe sent through the mail. These mechanical postage meters must be takenby the user to a “post office” to be reset. This enables a postalservice to capture payment for future services to be delivered.

A variation of the traditional postal meter is a newer technologyelectronic postage meter offered by Pitney Bowes, Inc., called “PERSONALPOST OFFICE”®. The electronic postage meter can be reset over telephonelines with charges made to a Pitney Bowes “POSTAGE BY PHONE”® account.Pitney Bowes also offers a “Post Office for the PC” product that enables“metered” post marks to be printed onto envelopes using a personalcomputer printer. A peripheral device attached to the personal computerserves as the postage repository, with postage downloaded via modem overtelephone lines.

Payment for the service provided by e-Parcel is via a prearranged fiatrate monthly charge, with the charge being determined upon registrationbased upon projected use and transmission file size. An alternativepayment plan, pay upon transfer service, has been advertised and chargesa fee for each file sect through an e-Parcel server. Payment for theservice provided by NetDox, Inc. is via NetDox server software licenses.

United Parcel Service, Inc. (UPS) has announced a mediated electronicdocument file delivery service based upon the NetDox product, and alsobased on another store and forward server based product called “Posta”available from Tumbleweed Software, Inc. The UPS system is representedto be an electronic document delivery service far which the userestablishes a billing account that will be charged for each documentfile sent through the UPS servers.

Facsimile transmissions across the PSTN, compliant with CCIPP Group 3facsimile standards, are relatively direct, immediate, and secure fromthird party interception. However, facsimile transmissions can pose amultitude of transmission management and processing problems for boththe sender and recipient. For facsimile transmissions, the “serviceproviders” are the local and long distance telephone companies thatcharge for the connect time required to send a fax.

Examples of devices using CCITT Group 3 facsimile transmission standardsare widely deployed fax machines available from a multitude ofmanufacturers, such as Hewlett Packard Corporation and PanasonicCorporation. Additional examples of devices employing the Group 3facsimile standard are the widely deployed PC fax modems available frommanufacturers such as US Robotics Corporation. Both fax machines and faxmodems communicate over the PSTN. An emerging technology is transmissionof fax images over the Internet. While fax devices enable directtransmission of a specific document image from a sender to a specificrecipient, the transmissions are not in the original file format of thedocument transmitted and typically suffer degraded visual quality. PCfax transmissions result in very large file sizes driving requirementsfor large storage capacity.

Unlike facsimile image transmissions, electronic file transfers acrossnetworks or through the PSTN using modems can render document files tothe recipient in native format, whether text, graphics, drawings, video,or sound. Such files may contain large format drawings or large pagecount documents. Unlike e-mail with attachment files, electronic filetransfers generally do not suffer problems with unpredictable delivery,third party mall server security, nor attachment file encodingcompatibility. However, mediated file transfer using client/servercommunication across wide area networks typically requires login to anetwork server, and can pose security risks when access is permitted forremote users or an organizationally unrelated third party.

File transfers through the PSTN using modems and the prior communicationarchitectures with accompanying computer programs usually require userattendance to effect the transfer between PCs. Alternatively, remotecontrol of one PC from another PC with attendant security risks isallowed. Thus, all of the mechanisms in the prior art for effectingelectronic file transfer, whether across the Internet, private intranetsor extranets, or through the PSTN, require a multitude of process stepsand a significant degree of user training.

An example of an approach designed to provide user access to documentfiles across a network is described in U.S. Pat. No. 5,634,057. Thispatent describes groupware, in which multiple users logged on to anetwork can interactively collaborate regarding various aspects ofdocuments such as form and content. Typically, groupware suffers fromits own complexity of use and does not enable direct transmission of aspecific file from one PC to another PC, or a simultaneous exchange withmultiple PCs.

Another example of an approach accomplishing file transfers directlyfrom a sending PC to a receiving PC through the PSTN, and in someinstances through the Internet, is a class of products described as“remoteware”. Within this category, specific products such as“pcAnywhere” available from Symantec Corporation, enable a user to loginfrom one computer to another computer and effectively take control ofthe operation and stored files of the computer onto which login wasaccomplished. However, direct transfer of files without the third partysecurity risk of login and control is not provided. Additionally,products, such as “DynaComm”. available from FutureSoft Engineering,Inc., are designed to provide dial-up terminal access to servers andmainframe computers across the PSTN. Such products are also typicallycapable of direct PC to PC transfer of files, provided a PC operator isavailable and ready at both the sending and receiving PC to setup theparameters and conditions under which the transfer will be made.

Another example of an approach that enables transmission of a singlefile from one PC to another PC interconnected to a Transmission ControlProtocol/Internet Protocol (TCP/IP) network is a demonstration computerprogram called “Wormhole” available over the Internet from MicrosoftCorporation. The purpose of this freeware computer program is todemonstrate how a socket data structure functions under the MicrosoftWindows operating system. This demonstration program is capable ofsending only one file to only one PC at a manually entered IP address.No restrictions can be placed on when or where files can be transmitted,nor from whom they are received. Simultaneous exchange of files withmore than one PC is not enabled nor suggested. Furthermore, no PSTNcommunication and no error checking or verification of the file transferis provided. Moreover, no indication of where files originate from isprovided. In addition, no communication or file controls are enabled.Also, it is not possible to request a file from a PC operating theWormhole computer program, nor is any form of file transport securityprovided.

Another example of an approach that enables direct PC to PCcommunication through the PSTN, developed by the current applicant, isthe AEGIS Document Imaging System (ADIS). In ADIS, document managementand communication functions are integrated to provide a system forcreating a virtual PC network interconnected through the PSTN. Inaddition to imaging capable PC equipment, ADIS requires specificcommunication hardware (e.g., SatisFAXtion 400 fax modem developed byIntel Corporation, available from Pure Data, Ltd., Ontario, Canada), anduses a file transfer mechanism built into the SatisFAXtion boardcontrolled by the ADIS computer program. No capability for direct filetransfer across the PSTN using widely deployed standard Hayes compatibledata modems, or across a TCP/IP network, is included in ADIS. Moreover,file requests can be made from one ADIS station by another ADIS station,but file requests can not be restricted to a specific station.

Another drawback of these conventional systems is that polling of aremote computer, when such capability is present, occurs serially. Thus,a long time is required to receive many files from many differentdestinations, particularly if one of the destinations is busy, causingthe polling computer to repeatedly attempt to contact me destinationbefore ultimately timing out.

Another example of a known file transfer system is DropChute+, availablefrom Hilgraeve, Inc. of Monroe Mich. Drop Chute+ utilises a single port,thus limiting communication to one other computer at one time.DropChute+ cannot communicate simultaneously (transfer files inparallel) with one or more other computers. Moreover, with DropChute+all transfers and commands take place on a single port, if more than oneevent is to occur, all events are multiplexed through the single port.Furthermore, it a user wants to send a file to a group of destinations,there is simply no way to do it under DropChute+.

Thus, there is a need for a system to provide immediate and secureassured delivery of documents from sender to recipient which retains thepositive aspects of the prior art, but does not suffer from itsshortcomings.

SUMMARY OF THE INVENTION

In view of the foregoing, in one aspect the present invention isdirected to providing a file authentication requesting device thatstores a computer program for requesting authentication of files indigital systems, the device comprising: a confirmation request systemthat generates a request for a confirmation receipt from a third partyauthentication authenticating the attributes of a file; a transferringsystem that transfers attributes of at least one file to beauthenticated to me third party authenticator from the device thatrequested the confirmation; and a receiving system that receives theconfirmation receipt comprising authenticated file attributes, afterauthentication by the third party authenticator; wherein, at least onefile authentication is received from the third party authenticate. Theat least one file to be authenticated may be received by the device as afile transfer from another device. An identification of at least one ofthe device or user of the device may be transferred along withattributes of the at least one file to be authenticated. Theauthentication may comprise digitally signing the confirmation receipt.The authentication may comprise a unique digital characterization offile attributes by a postal authority.

In another aspect, the invention provides a file authenticationprocessing device that stores a computer program for processing requestsfor authentication of files in digital systems, the device comprising, areceiving system that transfers attributes of at least one file to beauthenticated to the third party authenticator from the device thatrequested the confirmation; a processing system that processes aconfirmation receipt the processing comprising a unique digitalcharacterization of the file attributes, assuring at least in parttampering and modification detection; and a sending system that sendsthe confirmation receipt comprising authenticated file attributes to therequesting device, after processing by the third party authenticate;wherein, at least one file is authenticated by the third partyauthenticator. An identification of at least one of the requestingdevice or user of the requesting device may be transferred along withattributes of the at least one file to be authenticated. The uniquedigital characterization may comprise digitally signing at least thefile attributes or the confirmation receipt. The confirmation receiptmay incorporate at least the date and time of authentication, and anidentification of at least the requesting device. The unique digitalcharacterization of file attributes may comprise authentication by apostal authority.

In another aspect the invention provides a file authentication systemcomprising: an originating file authentication device originating arequest for a confirmation receipt from a third party authenticator, andtransferring attributes of at least one file to be authenticated to thethird party authenticator, a confirmation request processing device forprocessing a confirmation receipt by the third party authenticate, theprocessing comprising a unique digital characterization of the fileattributes, assuring at least in part tampering and modificationdetection; a transferring device for transferring the confirmationreceipt comprising authenticated file attributes, after processing bythe third party authenticates to the device that requested confirmation;wherein, the third party authenticator authenticates the attributes ofthe at least one file as requested by the device. An identification ofat least one of the requesting device or user of the requesting devicemay be transferred along with attributes of the at least one file to beauthenticated. The unique digital characterization may comprisedigitally signing at least the file attributes or the confirmationreceipt. The confirmation receipt may incorporate at least the date andtime of authentication, and an identification of at least the requestingdevice. The unique digital characterization of file attributes maycomprise authentication by a postal authority.

In another aspect the invention provides a computer readable medium thatstores a computer program for authentication of files in digitalsystems, the medium comprising: a transferring source code segment thattransfers attributes of at least one file to be authenticated to thethird party authenticator from the device that requested theconfirmation; a processing source code segment that processes aconfirmation receipt, the processing comprising a unique digitalcharacterization of the file attributes, assuring at least in parttampering and modification detection: a sending source code segment thatsends the confirmation receipt comprising authenticated file attributesto the requesting device, after processing by the third partyauthenticator; wherein, at least one file is authenticated by the thirdparty authenticator. An identification of at one of least the requestingdevice or user of the requesting device may be transferred along withattributes of the at least one file to be authenticated. The uniquedigital characterization may comprise digitally signing at least thefile attributes or the confirmation receipt. The confirmation receiptincorporates at least the date and time of authentication, and anidentification of at least the requesting device. The unique digitalcharacterization of file attributes may comprise authentication by apostal authority.

In another aspect the invention, provides a computer readable mediumthat stores a computer program for requesting authentication of files indigital systems, the medium comprising: a confirmation request sourcecode-segment that generates a request by a device for a confirmationreceipt from a third party authenticator authenticating the attributesof a file; a transferring source code segment that transfers attributesof at least one file to be authenticated to the third partyauthenticator from the device that requested the confirmation; areceiving source code segment that receives the confirmation receiptcomprising authenticated file attributes, after processing by the thirdparty authenticator; wherein, at least one file authentication isreceived from the third party authenticator. The at least one file to beauthenticated may be received by the device as a file transfer fromanother device. An identification of at least the device or user of thedevice may be transferred along with attributes of the at least one fileto be authenticated. The unique digital characterization may comprisedigitally signing the confirmation receipt. The unique digitalcharacterization of file attributes may comprise authentication by apostal authority.

In another embodiment, the invention provides a method forauthenticating files in digital systems, the method comprising:requesting a confirmation receipt from a third party authenticator by adevice, transferring attributes of the at least one file to beauthenticated to the third party authenticator by the device thatrequested the confirmation: processing a confirmation receipt by thethird party authenticator, the processing comprising a unique digitalcharacterization of the file attributes, assuring at least in parttampering and modification detection; transferring the confirmationreceipt comprising authenticated file attributes, after processing bythe third party authenticator, to the device that requestedconfirmation; wherein the third party authenticator authenticates theattributes of the at least one file as requested by the device. The atleast one file to be authenticated my be received by the device as afile transfer from another device. An identification of at least thedevice or user of the device may be transferred along with attributes ofthe at least one file to be authenticated. The unique digitalcharacterization may comprise digitally signing the confirmationreceipt. The confirmation receipt may incorporate at least the date andtime of authenticator and an identification of at least the requestingdevice. The unique digital characterization of file attributes maycomprise authentication by a postal authority.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is further described in the detailed descriptionwhich follows, by reference to the noted drawings by way of non-limitingexamples of preferred embodiments of the present invention, in whichlike reference numerals represent similar pads throughout several viewsof the drawings, and in which:

FIG. 1 is a schematic block diagram illustrating a system architecturewith a limited number of personal computers connected to variouscommunication pathways, according to an aspect of the present invention;

FIG. 2 is a flow diagram of exemplary logic of a main control modulewhich controls automated functions and user invoked functions accessedthrough a graphical user interface, according to an aspect of thepresent invention;

FIGS. 3A and 38 are flow diagrams of exemplary logic of a send filemodule which controls the file transmit functions, according to anaspect of the present invention;

FIGS. 4A, 4B and 4C are flow diagrams of exemplary logic of a receivefile module which controls the receive file functions, according to anaspect of the present invention;

FIG. 5 is a flow diagram showing exemplary logic for confirmationreceipt request processing, according to an aspect of the presentinvention;

FIG. 6 is a flow diagram of exemplary logic of a create index modulewhich creates an index of files that the user wishes to make availablefor request from another PC, according to an aspect of the presentinvention;

FIG. 7 is a flow diagram of exemplary logic of a request file modulewhich creates a request file pending event in the main control module,according to an aspect of the present invention;

FIG. 8 is a flow diagram of exemplary logic of a return requested filemodule which processes request for one or more files, or an index, andcreates pending events to return the requested files or indexes in themain control module, according to an aspect of the present invention;

FIG. 9 is a flow diagram of exemplary logic of a request credits modulewhich collects accounting information and the number of filetransmissions to be authorized, and creates an authorization requestpending event in the main control module, according to an aspect of thepresent invention;

FIG. 10 is a flow diagram of exemplary logic of a credits requestprocessing module which operates on a credit server, according to anaspect of the present invention;

FIG. 11 is a flow diagram of exemplary logic of an add credits modulewhich increments any remaining credits by the amount of the newauthorized credits, according to an aspect of the present invention;

FIG. 12 is a flow diagram of exemplary logic of a remove credits modulewhich decreases credits by the amount of the transfer cost, according toan aspect of the present invention;

FIG. 13 is a flow diagram of exemplary logic for a check for activeconnections module which periodically checks for active connections foreach address listed in the destination window, according to an aspect ofthe present invention;

FIG. 14 is a flow diagram showing exemplary logic for a third partyauthenticated processing of confirmation receipt requests, according toan aspect of the present invention;

FIG. 15 shows an example of an event log window which records filetransmission and receipt events, according to an aspect of the presentinvention;

FIG. 16 illustrates an example of en event properties window that showsthe properties and listed files of events listed in the event log file,according to an aspect of the present invention;

FIG. 17 illustrates examples of the transmit window for selecting filesto transfer, and the destination window for selecting destinations totransfer the file to, according to an aspect of the present invention;

FIG. 18 shows an example of an add/edit destination window for addingand editing the destination addresses in the destination window,according to an aspect of the present invention;

FIG. 19 shows an example of a select destination window for selectingthe destination for the file transfer and initiating the file transfer,according to an aspect of the present invention;

FIG. 20 shows alternative examples of a transmit window for selectingfiles to transfer, and the event properties window that shows theproperties and listed files of events listed to the event log file,according to an aspect of the present invention;

FIG. 21 shows alternative examples of a transmit window for selectingfiles to transfer, and the event properties window that shows theproperties and listed files of events listed in the event tog file,according to an aspect of the present invention;

FIG. 22 shows an example of a build index window for creating the indexof files that can be requested by a destination PC, according to anaspect of the present invention;

FIG. 23 shows an example of a request file window for requesting filesfrom another PC, according to an aspect of the present invention;

FIG. 24 shows alternative examples of a transmit window for selectingfiles to transfer, and the destination window for selecting destinationsto transfer the file to, along with a transport credit bar and creditrequest button, according to an aspect of the present invention; and

FIG. 25 is a flow diagram of exemplary logic of a send file schedulingmodule, according to an aspect of the present invention.

BRIEF DESCRIPTION OF APPENDICES

Appendix a is a source code listing of tool book script modules that arean exemplary implementation for generating the user interface for thefile transfer system of the present invention, the scripts modules beingcoded in tool book (available from Asymetrix Corporation of Bellevue,Wash.);

Appendix B is a C++ source code listing of exemplary dynamic linklibraries that implement the destination book features of the filetransfer system of the present invention;

Appendix C is a C++ source code listing of exemplary dynamic linklibraries that handle the file transferring functions of the filetransfer system of the present invention; and

Appendix D is a C++ source code listing of exemplary dynamic linklibraries that implement the logging and credit features of the filetransfer system of the present invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION

Referring now to FIG. 1, there is shown a schematic illustration of onepreferred embodiment of the present invention illustrating a systemarchitecture with a limited number of personal computers (PCs) 10connected to communications pathways, even though any number of PCs 10may be connected without limitation. FIG. 1 shows that the PCs 10 may beconnected to and may use one communications pathway (e.g., theInternet), another communications pathway (e.g., the public switchedtelephone network PSTN), or more than one communications pathway (e.g.,Internet and PSTN) simultaneously. The preferred embodiment of FIG. 1includes multiple PCs 10, without-limitation as to the maximum number ofPCs 10. Although each PC 10 is shown to be connected to the Internet,and/or the PSTN, alternative communications pathways may be employedsuch as private intranets and extranets.

Each PC 10 is preferably, but is not limited to, an “IBM compatible” x86or Pentium class machine, connected to a communications pathway.However, other computing devices, such as hand held computers,television set top boxes, mobile telephones, wearable computers,wireless computing devices, or any other device capable of connecting toa network and utilizing an operating system may be utilized. Of course,computers more advanced than Pentium class can be utilized as well. EachPC 10 can include a display monitor, a processor, memory such as ROM andRAM, a file storage device, a keyboard, a pointing device, acommunication interface, and a graphic user interface GUI operatingsystem having “drag & drop” functionality. Preferably, the operatingsystem is Microsoft Windows NT, Windows 95, Windows 98, or Windows 3.1x,all available from Microsoft Corp. However, the operating system may beany other graphically oriented operating system such as Mac OS availablefrom Apple Computer, Inc., Solaris, Xwindows, etc.

Each PC 10 runs a computer program incorporating functional modules,such as those illustrated in FIGS. 2-9 and 11-13, and has a GUIconsisting of windows, such as those illustrated in FIGS. 15 through 24described below. The file transfer system shown in FIG. 1, including thePCs 10 running the computer program and graphical user interface,enables direct transfer of electronic files between such interconnectedPCs 10 without requiring login to each other PC 10, and withoutintermediate storage of files on an intervening computer. A creditrequest processor 16 and independent certification processor 18 may alsobe provided and are discussed in detail below.

The GUI is generated by a computer program designed for a windowedoperating environment such as Microsoft Windows. The GUI consists ofmodules for controlling system communications and functions accessedfrom the GUI, and graphics modules that call or create display windows.Exemplary display windows include a transmit window, for indicatingcandidate files that can be transmitted, a destination window displayingcandidate PC destinations to which files can be transmitted, and anevent log window that displays transmitted files that have been sent orreceived. Furthermore, the GUI provides user controls for initializingand invoking system operating criteria via dialog windows.

In greater detail, the following describes the operating functions of apreferred embodiment of the computer program and graphical userinterface of the present invention from the perspective of both thesending PC and the receiving PC. Although the description is in terms ofsoftware, the present invention can also be implemented with firmware, acombination of hardware and software, or with only hardware such as awith a fixed function machine or application specific integratedcircuits, etc. In order to effect a file transfer, the computer programof a preferred embodiment of the present invention most be operating onboth the sending PC and the receiving PC during the time communicationis attempted. Other required operating conditions include activeconnection to the Internet, intranet or extranet, or a modem connectionto the PSTN; “power-on” or standby state at both the sending and thereceiving PC; and a windowed operating system such as Microsoft WindowsNT, Windows 95 or Windows 3.1 installed and operating on both thesending PC and the receiving PC.

In a preferred embodiment, control modules govern and supervise thetransmission and receipt of files across the connected communicationspathway. Moreover, a transmit window displays a list of files stored onthe file storage device. When files displayed in the transmit window areselected then dragged & dropped on to a graphical object, the drag &drop function of the windowed operating system internally creates a listof files with an associated file structure. The internal list is thenlinked by the operating system to the destination object represented bythe graphical object.

In a preferred embodiment, each candidate PC destination is displayed asa user created “nick name” in a destination window. Still further eachnick name may be a graphical object, invoked by the user, generated by acomputer program module and linked to a destination address (either IPaddress or PSTN number), and a computer program subroutine. When filesare dragged and dropped onto the destination object in the destinationwindow, a file list with associated file structure is created by thewindowed operating system and a control module displays a dialog boxprompting the user for confirmation that the selected files contained inthe file list are to be transmitted to the destination selected.

In a preferred embodiment, after the user confirms the files to betransmitted, a compression control module calls a compression subroutinethat copies and compresses the files contained in the file list, andstores the compressed file packet on the PCTs file storage device, inthe context of this specification, a “file packet” is preferably agrouped and compressed assembly of files, rather than a multiplexing orframe-transmission “packet”. Then, the control module sends a packetfile name and the address linked to the selected destination object to apending event log file.

Later, at a predetermined time, a control module initiates a connectionwith the destination PC via an appropriate communications pathway,identifies the sending PC by its name and destination address, thentransmits the packet containing the compressed files to the linkeddestination address across the connected communications pathway. Thecontrol module then indicates in an event log window by date, time, andcontent (which may include file names and associated file structure),when the transmission of the packet is complete.

The predetermined time is selected by the user. Thus, after selecting afile to send, the user may schedule the transfer to occur immediately,or at a later time and/or date. If the file transfer is scheduled forlater, the packet file name and destination address remain in a pendingevent log file until the designated date and time.

In preferred embodiments, a control module responds to inbound filetransmissions, captures, decompresses, and writes transmitted files tothe computer file storage device using the associated file structure,and creates a received file list that is linked to the stored files anddisplayed in the event log window showing date, time and content. Stillfurther, the control module initiates a continuous sequence for visiblyindicating when a packet has been received by a destination PC.Preferably, user selection of the received file listed in the event logwindow launches any application that has been associated with the filetype received.

System Control: FIG. 2 & FIG. 15

According to a preferred embodiment of the present invention, thecomputer program and graphical user interlace operating on eachinterconnected PC 10 provides for system control and user interaction. Amain control module, illustrated in FIG. 2, is provided for controllingautomated system functions as well as functions accessed through thegraphical user interface 1. When the user activates the computer programthrough the graphical user interface 1, the main control moduleinitializes system variables and links DLL files required for systemoperation at step S2.

A DLL is a dynamic link library and is a standard Microsoft Windowsconvention for storing functions called by application programs. DLLscan be part of the Windows operating system, application programinterfaces (APIs) from software vendors, or functions written for aspecific application. Table 1 illustrates exemplary DLLs for the presentinvention and their purpose.

TABLE 1 Type: Purpose: Windows standard dlls user GUI inferface shellDrag and drop support kernell File and memory functions Toolboxfunctions tb50dos.dll File and directory support tb50win.dll High levelGUI support tb50dlg.dll Common dialog functions Third Party APIs saxcom10.dll Modem file transfer functions compress.dll Compression functionsCustom DLLs adis.dll Destination book functions Indexing functionshyper.dll Log functions ftpip.dll Internet file transfer functions

Saxcom 10.dll is available from Sax Software Corporation of Eugene,Oregon and implements several file transfer protocols for use withanalog telephones, including Zmodem.

Operation of the main control module in each PC 10 is centered on apending events file. The pending events file contains a list of eventsinitiated by user interactions or communication requests from otherinterconnected PCs 10. At step S3 the main control module monitors thecontents of the pending events file to determine if any pending sendevents exist. If pending send events are detected, at step S4 the maincontrol module calls a send file module, described below with referenceto FIG. 3. After the send file module executes at step S4, or if nopending send events are detected at step S3, the pending event file isagain monitored to determine if any pending receive events are presentat step S5. If pending receive events are detected at step S5, the maincontrol module calls a receive file module at step S6, described belowwith reference to FIG. 4. Otherwise, or after the receive file moduleexecutes, at step S7 user events are processed.

User events originate in response to user interaction with controlwindows provided by the graphical user interface 1, and resultingcomputer program functions initiated by such user interactions. Anexemplary user event is scheduling a file transfer of a user selectedfile. Exemplary events are shown to originate from modules 2-7 shown inFIG. 2. Each module 2-7 is invoked from the graphical user interface 1.Processing the user events involves executing module specific logic andis described below.

At step S9, internet protocol (IP) connections ere checked by a functiondescribed below with reference to FIG. 17. Subsequently, the logicreturns to step S3 and repeats as described above.

Referring to the display screen shown in FIG. 15, both completed andpending events 24 can be viewed in an event log window, such as thatshown in FIG. 15. Furthermore, file transfers are logged recording thedate, time, and content of the transfer at both the sending andreceiving PCs. Clicking on each lab 20 at the top of the event logwindow displays all events having the selected property indicated on theselected tab (e.g. failed, pending, etc.). The Decrypt button 21launches a function (described below) which decrypts received files thatwere encrypted by the sender. Decryption can also be implemented withoutmanual intervention depending on the functionality ofencryption/decryption programs integrated into the file transfer system.The Close bog button 22 closes the event log window. Preferably, thecontents of the event log window includes for each event, the sender andreceiver of the file, the time and date the file transfer occurred,whether the event was a send event or a receive event, and the status ofthe file transfer. Exemplary file transfer statuses are: completedtransfer, pending transfer and failed transfer. An additional symbole.g., R or U, may be displayed to indicate whether a file has been read.When employing the additional symbols R signifies the file has beenread, and U signifies that the file has not been read

File Transfer System: See FIG. 3 and FIG. 4

An aspect of the present invention is the file transfer system. Thereare several parts to such a system. The first is the Windows Socketssystem. In the present invention, to send a file from one interconnectedPC to another, each PC must be able to detect communication requests forother PCs. A preferred system for detecting communication requestsrequires each PC to create at least one data structure, called a socket,that listens for communication requests at a specific port on each PC.In a preferred embodiment, one listening port is created at port 789.However, any port or ports can be utilized, as long as all versions ofthe computer program on each interconnected PC recognize and connect tothe ports used to initiate a transfer. As a result of the establishedsocket, each PC listens continuously for a communication request fromanother PC.

In a preferred embodiment, a PC connection to the Internet or privateintranets and extranets using TCP/IP is established by invokingsubroutines which create data structures called sockets that enablecommunication using TCP/IP standards. A listening socket is establishedthat permits the PC to monitor the Internet, intranet or extranet forinbound communication requests initiated by other PCs. When an inboundcommunication request is detected, a control module in the receiving PCevaluates the request within the context of selective acceptancecriteria prior to accepting receipt of the communication request. Inother words, the receiving PC automatically decides whether it willaccept communication from the sending PC based on criteria such asauthenticated identity. The receiving PC terminates transmissions fromunauthorized PC destinations.

The selective acceptance criteria is established during systeminitialization. The receiving PC evaluates whether it will accept arequest according to various user defined criteria. For example, thereceiving PC may examine the addresses in the destination file andaccept communication only from addresses listed in the destination file.Alternatively, the receiving PC may only allow receipt of communicationsfrom PCs using software having selected serial numbers. For example,license codes initialized during setup at each system PC can be utilizedautomatically in conjunction with the destination addresses to furtherauthenticate the source identity for inbound communication requests.Alternatively, encrypted authentication codes initialized during setupat each system PC can be utilized in conjunction with the destinationaddresses and/or license codes to further authenticate the sourceidentity for inbound communication requests. The user may configure theacceptance criteria at installation and may change the acceptancecriteria at any time thereafter.

In preferred embodiments, if a control module at the receiving PCaccepts the communication request from a sending PC, a separate socketis established by control modules at both the sending and receiving PCs.The file transfer is via the separate sockets. Meanwhile, the listeningsockets at both the sending PC and the receiving PC are maintained. Ascommunication requests from sending PCs are detected and accepted by PCsengaged in sending or receiving one or more concurrent and ongoingtransmissions, multiple sockets enabling simultaneous file transfers arecreated by a control module at each PC receiving such communicationrequests. In preferred embodiments, a control module in a sending orreceiving PC creates and places in a linked list one file transfersocket for each additional, concurrent inbound or outboundcommunication. This list facilitates managing the flow of filetransfers. Thus, multiple discrete connections can be established withmultiple remote computers across the various communications pathways, towhich the local computer is connected.

The process of sending a file is now described with reference to FIG. 3.Initially at step S30, it is determined whether sufficient credits existfor transferring the file. The credit sufficiency analysis is describedbelow. If insufficient credits are found, at step S32 additional creditsmay be requested as described below. If sufficient credits are found, atstep S34 it is determined whether the transfer is intended to be anInternet (or intranet/extranet) transfer.

If the transfer is an Internet transfer, at step S38 another socket iscreated. In addition, the sending PC connects to the listening socket enthe remote PC at port 789. When another transmission is alreadyexecuting, the newly created socket is added to the linked list ofsockets in use. The program traverses the list, giving sockets time toperform their actions. Thus, multiple transactions can occursubstantially simultaneously. In practical terms, the number oftransactions that can be handled by the system depends on factors suchas communications speed and processor time and speed.

At step S38 if is determined whether the connection to the remote PC issuccessful. If the connection has not been established, at step S40 itis determined whether the sending PC previously attempted to connect tothe remote PC. If a previous attempt occurred, it is determined whethera maximum number of attempts have occurred; in a preferred embodimentthree attempts. Thus, if three unsuccessful attempts occurred (anynumber can be specified), at step S48 the logic terminates execution andan error is logged indicating that a connection cannot be establishedwith the remote PC. Alternatively, the local computer may be setup todelay the file transfer until the remote destination computer has anactive connection to the communications pathway at a known address. Ifthe number of attempts is less than the maximum number of attemptsallowed, the sending PC again attempts to connect to the remote PC atstep S36.

If the connection is successfully established, at step S42 the sendingPC sends information about the file to be sent and about the sending PC,thus informing the remote PC of where the transmission is originating.The sending PC then waits for the remote PC to send an address to whichthe file can be sent. If the data received from the remote PCcorresponds to a valid data port assignment, the logic proceeds to stepS48. Otherwise the logic proceeds to step S46 where the logic terminatesexecution and an error is logged indicating that an invalid reply wasreceived.

At step S48 upon receiving a valid data pod assignment, a new datasocket is created and a connection is established between the new datasocket and a data port corresponding to the data port assignmentreceived from the remote PC. In addition, a time-out timer commences andthe starting point of the file is determined. When another transmissionis already executing, the newly created data socket is added to a linkedlist of data sockets.

At step S50 data is sent to the remote PC, in a preferred embodiment,the file being transferred is transmitted 2048 bytes at a time. Thus,the first 2048 bytes are transmitted at step S50. Each time data is sentat step S50, the time-out is reset to zero. If the time-out reaches amaximum time, the connection is terminated and the data socket isdestroyed.

At step S52 it is preferably determined whether other data sockets existin the data socket linked list if other data sockets exist, at step S54data associated with the next data socket is sent, and the logic repeatsfrom step S52 until no other data sockets are found.

At step S56 it is determined whether the end of the file has beenreached. If the end of the file has not been reached, the logic returnsto step S50 and repeats. If the end of the file has been reached, atstep S58 the connection is terminated, the data socket is destroyed, andthe remove credits module is called. Finally, at step S60 the event isrecorded in the log file.

A preferred embodiment of the present invention utilizes a singledesignated User Datagram Protocol (UDP) command port to exchange filecharacteristic information, user authentication information, and toinitiate a transfer. Subsequently, a TCP data pod is opened to exchangethe file content. The UDP command port allows faster connections andquicker data transfer than a TCP port. However, a TCP port is morereliable for data exchange. Consequently, a preferred process forsending a file is as follows:

1) A sender initiates a transfer by sending file characteristicinformation and sender identification/authentication information to aspecified UDP command port on a destination computer at a specific IPaddress. If the transfer is accepted, a data port is created randomlywithin a range of possible specified pods and its number is returned onthe UDP connection. Otherwise, a notification that the transfer isrejected is sent, and the UDP connection is closed. Finally, the UDPcommand port waits for new transfers to be initiated.

2) if the transfer is accepted by the recipient, the sender connects tothe TCP data pen returned by the recipient over the UDP connection andstarts sending the file. Both the recipient and sender resume“listening” on the UDP port for transfers initiated by other computers.This is accomplished while the file transfer over the TCP port is inprogress. The process is repealed and managed for any number ofsubsequently initiated file transfers. Thus, multiple, simultaneous filetransfers can be accomplished with any number of other computers, withonly one instance of the computer program open and running. Advantagesof the present invention include a simple user interface and operatingapproach, great efficiency in system resource utilization, and fast filetransfer speed.

3) The receiver closes the connection when me file size information(characteristic) sent over the UDP connection that initiated me transfermatches the size of the file received or the sender closes itsconnection due to an error.

In other preferred embodiments of the indention, more than one UDPcommand port listens for or initiate file exchanges. To initiate atransfer, a sender PC randomly and automatically selects the UDP portfrom a set of specified ports. For example, one, two, or more UDP podsat predetermined port numbers could be designated as listening ports. Asender PC initiates a file exchange on a UDP port randomly selected fromthe set of specific listening ports. The recipient monitors the set ofspecified pods for initiated file transfers and responds on the UDR portutilized by a prospective sender to acknowledge the connection andreturn a designated data port. This configuration also lowers theprobability of a “collision” in the event that two or more computersattempt to communicate with the same PC at exactly the same time.Alternatively, if such collisions old occur, the attempted communicationcan be automatically retried at a random interval later in time.

If the file transfer is determined to be a PSTN transfer at step S34, atstep S62 the sending PC dials the telephone number associated with theremote PC. At step S64 it is determined whether a connection has beensuccessfully established. If no connection was established, the logicproceeds to step S40 where it is determined whether a connection attemptoccurred previously, if a previous attempt occurred, it is determinedwhether a maximum number of attempts have occurred; in a preferredembodiment three attempts. Thus, if three unsuccessful attemptsoccurred, at step S46 the logic terminates execution and an error islogged indicating that a connection cannot be established with theremote PC. However, if the number of attempts is less than the maximumnumber of attempts allowed, the sending PC again attempts to connect tothe remote PC at step S62.

After the connection is established handshaking occurs, and at step S66the sending PC sends an identifier and waits for a response from theremote PC. At step S68 if a response is not received, at step S48 thelogic terminates execution and an error is logged. If a response isreceived, at step S70 the sending PC sends file and station informationto the remote machine. Then, the sending PC waits for a reply from theremote PC. If no reply is received, at step S46 the logic term malesexecution and an error is logged. Once the reply is received, at stepS74 the file is sent to the remote PC utilizing a file transferprotocol. In a profaned embodiment, Zmodem is the file transferprotocol. Upon completing the file transfer, the connection isterminated. Subsequently, the transfer status of the sent file islegged, and the logic proceeds to step S58 to continue as previouslydescribed.

the logic which executes at the remote/receiving computer is nowdescribed with reference to FIG. 4. Initially at step 400 it isdetermined whether the transfer will be an Internet (orintranet/extranet) transfer. If the transfer is expected to be anInternet transfer, at step 402 a socket is created on port 789 and thereceiving PC waits for a connection. When someone connects, at step 404all sent data is read. Then, at step 406 the received data (i.e., ID) iscompared to IDs within a destination book of IDs from which transferswill be accepted. If the received ID is not found in the destinationbock, at step 410 an error occurs and the connection is terminated. Ifthe ID is found at step 408, at step 412 it is determined whether thereceived data is valid. If the data is not valid, at step 410 a negativeacknowledgment is sent to the sending PC and the connection isterminated.

If the data is valid, at step 414 it is determined if the received dataindicates an index or file request. If the received data indicates anindex or file request, at step 415 the request is processed. Otherwise,at step 416 it is determined whether the received data indicates acredit authorization. If the data indicates a credit authorization, atstep 418 transmission credits are added, described in greater detailwith reference to FIG. 11. Otherwise, at step 420 it is determinedwhether the received data indicates a request for identification. If thereceived data indicates a request for identification, at step 422 aresponse is sent to the requesting PC with the ID of the receiving PC.Otherwise it is determined whether the received data is a partial fileat step 424.

The partial file determination occurs to decide whether an interruptedtransfer is being resumed, or whether a now transfer is beginning. Thus,if the received data is a partial file, at step 426 a starting point isset to the size of the partial file because part of the file must beresent. In other words, the receiving machine informs the sendingmachine of where to resume the transmission depending on what portion ofthe file was previously received. Subsequently, at step 430 a socket iscreated on a random port, the random port address is sent to the sendingPC, and a time-out timer is set. If the received data is not a partialfile, i.e., a new transfer is beginning, at step 426 the starting pointis set to zero. Subsequently, the logic proceeds to step 430.

From step 430, the logic proceeds to step 432 where the receiving PCwaits for data on the port. When data is received, the time-out counteris again reset. Preferably, there is an automatic visible indication ofreceipt of files at the receiving PC. At step 434 it is determinedwhether other sockets exist, if other sockets do exist, at step 436 datais received for the next socket. Subsequently, the logic returns to step434 and repeats until no other sockets are found. Similar to the sendingPC, the data sockets may be stored on the receiving PC in a linked list.

At step 438 if is determined whether a file transfer is complete or ifdata times out. If the data times out, the connection is terminated andthe socket is destroyed. Also, if the connection terminated on its own,the socket is destroyed. If no transfer is found to have completed, thelogic returns to step 432 and repeats. When a file transfer is complete,at step 440 it is determined whether the received file is the same sizeas expected, in other words, the file size is compared to the sizeindicated in the file data sent at step S42. If the sizes do notcoincide, at step 442 a receive error is logged. Otherwise, if the filesizes are the same, transmission is deemed successful and the logicproceeds to step 444.

At step 444 the event received is logged, the packet is unpacked, andthe received files are stored on the receiving PC's storage device.Although in the previous description the sending PC is identified, byname and IP address, to the receiving PC upon initial connection, theidentification can come at a later time. However, preferably the sendingPC is identified to the receiving PC before the receiving PC opens thereceived files. Next, at step 446 logic described with reference to FIG.5 executes to process confirmation receipt requests. Subsequently, thelogic proceeds to step 448.

At step 448 it is determined if any other data sockets exist. Ifadditional data sockets are found, the logic returns to step 432 and theprocessing repeats. If no other data sockets are found, the logic flowsto step 460 where an automatic update process executes.

Verifying the data is handled by the TCP/IP protocol that underlies theWindows Socket specification. Because the TCP/IP protocol handlessending and receiving data, file verification is automatic. That is,TCP/IP is an error responsive protocol that checks each TCP packet usingcyclic redundancy checking (CRC) and retransmits bad packets.Accordingly if a file is assembled from successfully received TCPpackets, the probability that the received file is error-free is veryhigh. Thus, it is only necessary to verify whether the entire file wasreceived. This is accomplished by verifying that the size of the datatransmitted matches the specified size of the file that is received. Thefile size specification is sent with the file being transmitted andarrives at the receiving PC at the beginning of the transmission.

For modem transfers, the process is different. Thus, if the transfer isdetermined not to be an interne transfer at step 400, at step 460 themodem is set to auto answer mode, so that it will answer if called.Preferably the modem is set to auto answer mode during initialization atstep S2 on each PC.

After the modem is initialized, at step 462 the receiving PC waits for atelephone call. Upon receiving a call, the receiving PC answers andreads a data stream from the modem to determine the sending PCidentifier, if no data is received before a time out occurs, theconnection is terminated. If data is received, the receiving PC sands aresponse to the sending PC, which includes an identifier of thereceiving PC.

At step 464 file data validity is checked, if the data is invalid, areceive error is logged at step 442. Otherwise if the data is valid, atstep 466 the download commences with an agreed upon model protocol,preferably, Zmodem that checks each packet using CRC and retransmits badpackets. Subsequently, the logic proceeds to step 468 to determinewhether the received file is the same size as expected, indicating asuccessful transfer. If the file is not the expected size, at step 442 areceive error is logged. If the received file is the expected size, atstep 470 a receive event is logged, and the received packet is unpackedand stored on a storage device. Next, at step 472 logic described withreference to FIG. 5 executes to process confirmation receipt requests.Subsequently, the logic proceeds to step 450 and executes as previouslydescribed.

By using the Zmodem protocol, error checking is automatic. However, onceagain the file size is checked to ensure that the received file is thesize if is supposed to be.

Confirmation Receipt Request and Third Party Authentication: See FIG. 5& FIG. 14

According to another preferred embodiment, the present invention enablesa sending PC to request from a recipient PC, confirmation of theattributes of a transferred file packet. The confirmation is a returnedfile containing a received file list, along with the identity of bothrecipient and sender, as well as various other attributes. The receiptfile is returned from the recipient to the sender directly or through athird party authenticator 18 (FIG. 1) without requiring any action bythe recipient computer's user. The sender may designate whetherconfirmation is by direct return or through a third party authenticator18 common to all users. The destination address of the third partyauthenticator 18 is either incorporated into the computer program priorto distribution to users or entered by a user prior to initiating theconfirmation requests as part of setup of the computer program on thesending PC.

A control module on the recipient PC, upon receipt of a request for aconfirmation of the attributes of a transferred file packet, records thecontent of the received packet. This may be set up to occur before orafter it is decrypted and decompressed. By creating a file list, thecontent files are written into the file structure of the recipientcomputer's storage device. Still further, the control module on therecipient PC combines into a confirmation receipt file attributes of thetransferred file packet. The attributes may include (1) a file list thatdelineates the names of files actually found to be present in a receivedpacket, whether containing encrypted or unencrypted files, (2) the sizeof the files received, (3) the identity of the sending PC (point oforigin) as received with the file packet, (4) the identity of therecipient PC, (6) the date of packet receipt, (8) the time of packetreceipt, and (7) the electronic fingerprint (bash) of the transmittedfiles. Alternatively, the confirmation receipt may be setup to provideonly verification of a file transfer action accomplished at a specificdate, time, and destination.

Still further, if direct return has been requested by the sending PC,the control module on the recipient PC creates a pending event forimmediate return of the confirmation receipt file to the sending PC,designating the corresponding destination address. Moreover, if therequested confirmation is designated by the sender to be returnedthrough a third party authenticator, the control module on the recipientPC creates a pending event for return of the confirmation receipt fileto the sending PC through the third party authenticator, designating thecorresponding destination address. The confirmation receipt file istransferred to the third party authenticator along with the destinationaddress of the sending PC that requested the confirmation. Stillfurther, the third party authenticator, upon receipt of the confirmationreceipt file, processes the file stamping a unique digitalcharacterization of the file using commercially available fileauthentication application programs. The file authentication applicationprograms are designed to create files for which any tampering ormodification can be readily detected. Finally, the authenticatedconfirmation receipt file is transferred, after processing by the thirdparty authenticator, to the destination address of the sending PC thatrequested confirmation. A copy of the authenticated confirmation receiptmay also be sent to the recipient of the associated file transfer.

The logic for processing confirmation receipt requests is now describedwith reference to FIG. 5. Initially, at step 500 it is determinedwhether a receipt has been requested if no receipt has been requested,at step 502 the logic returns to FIG. 4. Otherwise, at step 504 a filelist is created. Preferably, the file list includes the attributes ofthe transferred files such as the files sizes, end the dales and timesthe file were created. Next, at step 506 a text file is created. Thetext file preferably includes the sending PC's identification, thereceiving PC's identification, and the date and time the file packet wasreceived. Then, at step 508 a confirmation receipt file is created. Theconfirmation receipt file is a combination of the file list and the textfile. Subsequently, at step S10 an immediate send event is created forthe confirmation file.

At step 512 it is determined whether direct return has been requested.If direct return has been requested, at step 514 a pending event iscreated with the PC that requested the direct return as the destinationaddress. If direct return has not been requested, third partyauthentication has been requested. Thus, at step 610 a pending event iscreated with an independent authenticator designated as the destinationaddress. Alter completing either step 514 or step 516. the logic returnsto FIG. 4 at step S15.

Exemplary logic which executes at the third party authenticating machineis now described with reference to FIG. 14. initially at step 1400 asocket is created for listening, in a preferred embodiment, the socketis at port 789. Then at step 1402 the third party authenticator listenson the listening port. When data is received, at step 1404 it isdetermined whether a request is being sent. It a request is not beingsent, the logic returns to step 1402 and repeats. If a request is beingsent, at step 1406 a random data socket is created and assigned to aport, the number of which is sent to the requesting PC. Subsequently, atstep 1408 the confirmation receipt file is received on the assignedport, and at step 1410, the file is authenticated. Next, at step 1412 animmediate send event for the authenticated confirmation receipt file iscreated, and at step 1414 the requestor is sent the destination addressreceived with the request. Finally, at step 1416 it is determinedwhether other data sockets exist, if other data sockets do exist, theloose returns to step 1408 and repeats, it no other data sachets exist,the logic returns to step 1402 and repeats.

Event Log: See FIG. 15

All communication events are automatically logged by the computerprogram in an event log file, characterized by event properties such asdate, time, file structure, and file name. The user can view andinteract with logged events listed in the event log file by using acontrol window such as that shown in FIG. 15. Received files can beopened for viewing directly from the Event log window, provided the fileformats of the received files have been associated with an appropriateapplication program available on the receiving PC. Opening the files canbe accomplished by selecting an event 24 listed in the Event Log windowusing the pointing device, then initiating control commands using thePC's pointing device or keyboard which opens a control window such asthat shown in FIG. 16. The control window shown in FIG. 16 displays theproperties of the logged event. Listed files can be opened by selectingthe file 25, then initiating control commands using the PC's pointingdevice or keyboard which opens the fife using an associated applicationprogram available on the PC. If no application program has beenassociated with the format of the listed file, a message informing theuser or prompting user action is displayed. The Cancel button 26 closesthe event properties window. The View Receipt button 27 displays anyreturn receipt associated with a selected event.

Selecting and Sending Files/Packets: See FIG. 17, FIG. 19, FIG. 20, FIG.21 & FIG. 25

The user at any interconnected PC of the present invention can initiatea send file event in a variety of ways. For example, by interacting witha control window such as the window shown in FIG. 17, the user canutilize the PC's pointing device to select files listed in a transmitwindow 23. Subsequently, by invoking the drag & drop function of thewindows operating system, the user can drop files on destination objects30 in the destination window. In response to dropping the file on thedestination object 30, a file list created by the windows operatingsystem is linked to the address of the destination object 30 and thefile will be sent. Preferably, the file structure resident at thetransmitting PC is replicated at the receiving PC for each sent file.

In a preferred embodiment, manual confirmation is required for each fileselected to be sent to each PC destination. The manual confirmationrequires user action in order to transfer each file. An automatedscreening of file transfer authorization may also be provided which onlypermits authorized transfers to occur. The automated screening may occurprior to transmission to each PC destination for each file to betransferred.

The buttons at the bottom of the destination window may also be employedin a preferred embodiment. Button 34 opens other destination windows.Sutton 36 minimizes the destination window. Button 32 opens the transmitwindow 28.

Alternatively, a packet or file can be selected via the windowsdisplayed in FIGS. 20 and 21, and the destination can be selected viathe window shown in FIG. 19. According to the procedure employing thewindows in FIGS. 19-21, the user selects a file or packet and creates asend event which can be scheduled either as an immediate transfer or adelayed transfer.

In FIG. 20, a Drives drop down list 60 enables selecting a disk drivethat stores the files to be sent. When a drive is selected, thedirectory structure is displayed in a display field 62 showingdirectories, subdirectories, and files. After the user selects a file,the selected file is displayed in a display field 64, along with thecorresponding file structure. Preferably, any selected files shown inthe display field 64 will be compressed (all together if multiple fileshave been selected) into a file packet (also referred to simply as apacket) before being transmitted.

Clicking on a Description box 66 results in a user prompt 68 whichpermits the user to name the file packet and add a text message thatwill be sent along with the selected files. In a preferred embodiment,text identifying the users name, organization, and address areautomatically inserted. A text message may also be inserted info thedialog window by the user. Still further, the inserted text is thenlinked, by a control module to the list of files to be compressed by thecompression subroutine into a packet for transmission by a controlmodule to a linked PC destination address. The text information aboutthe sender and text messages contained in received packets are displayedin the event log window when associated received files are selected bythe user.

In a preferred embodiment, one or more files may be selected from one ormore directories in the file structure for compression, by a compressioncontrol module, into a packet for transmission to a destination PCaddress. The text message embedded with the files to be transmittedprior to compression at the sending computer is readily visible afterdecompression at the receiving computer. However, when encryption isenabled, text messages can be embedded with the files to be transmittedprior to encryption at the sending PC and made readily visible at thereceiving PC after decryption. Alternatively, the text messages can beembedded with the fifes to be transmitted after file encryption at thesending PC. Consequently the text messages are readily visible prior tofile decryption at the receiving PC. The text messages are saved in atext file that the receiving computer recognizes and consequentlydisplays upon receipt.

If the Description box 66 is not checked, no user prompt 63 isdisplayed, and the packet is created with a standard message and arandom number as a name. The user prompt 68 may also be displayed when aCompress button 65 is selected. Clicking an OK button 69 initiates acompression function by calling me zip compression function in thecompress.dll that creates the file packet. The user prompt 68 is thenclosed and the Compress button 65 is replaced by a Next button thatenables the user to switch to the select destination window (FIG. 19).

If the user wishes to send a previously created file packet, a sendexisting packets window (FIG. 21) can be reached via the Packet menu 50in FIG. 19, or in any other screen where the Packet menu appears. InFIG. 21, selecting a packet 70 then clicking on the Next button 71switches the user to the select destination window (FIG. 19), where thedestination for the selected packet can be designated. Double clickingon a packet 70 results in a display 72 showing the contents 73 of thepacket and any associated message 74. Clicking the Cancel button 75closes the display 72 The Clear Entry button 76 deletes any selectedpacket 70. The Clear List button 77 deletes all packets 70 in the listof displayed packets.

The select destination window for selecting a destination to send thefile to is now described with reference to FIG. 19. The Packet menu 50enables initiating a file transfer, index request, file request, or logdisplay. A Control menu 51 offers options for establishing a link to anactive Internet/intranet/extranet connection and/or initializing amodem. An index menu 52 permits accessing the index build/edit function,and a volume manager. The volume manager enables naming and deletingvolumes, which are logical divisions within an index. A Setup menu 53enables modifying the computer program setup in terms of directories,modern parameters, user information, encryption program interface, andalso enables access to destination books which create lists ofdestinations. A Help menu 54 accesses usage instructions.

A Change button 55 accesses destination books. A Browse button 56facilitates finding previously created file packets. The packets aredisplayed in a dialog box that appears when the Browse button 58 isselected. A Previous button 57 returns the display to the previousdisplay screen. A drop down list 58 displays candidate destinations fromwhich the user may select the destination to which files will be sent. ASend button 58 initiates a transfer of selected files to the selecteddestination.

Another procedure for sending a selected file to a selected destinationis now described. While the user is working within an applicationprogram, the user may save the working file to a directory associatedwith a particular destination, i.e., destination linked directory (DLD).Files may be saved to the directory utilizing a Save As option, or maybe automatically written into one or more DLDs as automatic output froma companion application program. Subsequently, all files within thedirectory (i.e., DLD) to which the files were saved are sent to thedestination associated with the directory. In a preferred embodiment,the transfer occurs immediately after the file is saved. However, thetransport interval may be set for immediate or delayed time periods.Thus, by saving files to the directory associated with the particulardestination or group of destinations, the files will be sent to thatdestination or group of destinations without additional user action.Multiple directories, each associated with a particular destination, mayalso be employed allowing the user to select the destination to whichthe file will be sent. These directories may be created at the time adestination is defined in the destination book by the user, DLDs enableintegration of the present invention with other application programs atthe operating system level without the use of an application programminginterface (API).

Whenever a file is written into a DLD, the file is sent to thedestination that has been associated with the DLD, then deleted from theDLD. A user option allows the file to be written into the DLD and thensaved into an archive file other than the DLD before the file isdeleted. The present invention allows the user to create multipledirectories associated with destinations and store them in thedestination book. Whenever a user places a file in one of thosedirectories. It is sent to the associated destination. This enablesseamless interfaces between large groups of computers over wide areanetworks. Computers that generate large numbers of files (such asinvoices) requiring distribution to a large number of recipients can beautomatically and directly linked to the destination computer using DLDstructures.

The receiving computer that receives the transfer from the DLD must beactively connected to a communications pathway accessible to the sendingcomputer. If the receiving computer is not actively connected, thesending computer can repeatedly attempt to transfer the file, in apreferred embodiment, the attempts stop after a user selected time-outperiod elapses. Alternately, the sending computer may wait, until it isdetermined that the receiving computer has become connected. Thereceiving computer receives the files in a directory designated toreceive files by the receiving computer's user. A discrete connection isestablished for each file transfer initiated with each receiving PC, asdescribed above.

Referring to FIG. 25, an exemplary process for scheduling a file sendevent is now described. Initially at step 2500 a file/packet anddestination are selected according to one of the procedures describedabove. Next, at step 2502 it is determined whether the user isauthorized to send the selected file to the selected destination ifauthorization is not confirmed, at step 2504 the user is asked toconfirm that the selected destination is the destination to which theuser actually intends to send the file, if confirmation is not received,at step 2506 the file transfer is aborted. Otherwise, and also whenauthorization occurs at step 2502 at step 2508 it is determined whethera previously established packet is being sent. If the packet has not yetbeen established, at steps 2510, 2512, and 2514 the packet iscompressed, link identification information and authentication codes arecreated, and the packet is encrypted.

After the compression, and also when it is determined mat the packetalready exists, at step 2516 it is determined whether the filetransmission is to occur now or later, if the transfer is to occurlater, at step 2518 a scheduler is opened, and at step 2520 the userinputs the date and the time when the file transfer should occur.Subsequently, and also when the file is to be sent immediately, at step2522 a send event is created.

Finally, at step 2524 the send event is scheduled as a pending event inthe main control module. At this point, the computer program treats thefie like any other pending event set up by the user. The program isconstantly in the process of monitoring the queues and sending anypending events found with a time that is earlier than or equal to thecurrent time.

Setting Up a Destination: FIG. 17, FIG. 18 & FIG. 19

In preferred embodiments, a user function is provided to invoke adestination window, with which one or more destination files may becreated. The destination window may be used to select a destination fileand to add, delete or modify destinations in a destination file. Adestination address may be selected from a destination window by theuser for use by a control module to transmit a packet, in preferredembodiments, a user function is provided to invoke a dialog window fromwhich the user may set a specific date and time when a control modulewill initiate transmission of a specific packet.

In preferred embodiments, a user function is provided to add destinationPC addresses as nick name objects in a destination window. The nick nameobjects added to the destination window are linked to the specificdestination addresses contained in the destination file. Preferably thenumber of possible destination addresses allowed as destination targetsfor a sending PC is controlled by setting a preset non-user-adjustablelimit (a locking limit) in a control module for the number of entriesallowed in the destination file. Also, the number of destination filesallowed for a sending PC is controlled by setting a locking limit in acontrol module for the number of destination files that can be createdor viewed. The locking limit may be preset in the software by thesoftware developer/manufacture during installation disk productionbefore the software is shipped to a user for installation onto thecomputer.

In preferred embodiments, a user function is provided to invoke a dialogwindow that enables modification of a destination address from adestination window. Moreover, a user function is provided to invoke adialog window from which the user may create or select for displayadditional destination windows, in preferred embodiments, a userfunction is provided to launch a file structure display window from adestination window.

According to a preferred embodiment, a discrete destination andassociated address can be defined or modified, and saved in adestination file by user interaction with a control window such as thatshown in FIG. 18. Once defined and saved a destination file can beselected and displayed in a destination window such as that shown inFIG. 19, and can be linked to a destination object in a destinationwindow such as that shown in FIG. 17. A destination file can also belinked to a directory to create a DLD.

A procedure is now described for adding or modifying a destinationaccording to a preferred embodiment. The Setup menu 53 is selected toaccess the window shown in FIG. 18. Then, the user selects the Newbutton 40, or selects a destination and selects the Edit button 42.Clicking on button 40 results in a dialog box display that enables entryof destination information comprising name, address, address type (e.g.,PSTN number, IP address number), or creation of groups of destinations.A group of destinations allows a file transfer to be made to alldestinations within the group with a single user action. Button 42 isused to edit parameters of an exiting destination. Clicking on the Editbutton 42 results in a dialog box display that enables modification ofdestination information.

For modern destinations, the user enters the telephone number of themodern destination. For Internet addresses, the user enters the IPaddress of the destination. After inputting the information, the userselects a Finished button 48 and the destination is added to thedestination book. The Finished button 48 closes the destination bookwindow. A box (not shown) may also be checked causing a destinationlinked directory to be setup for the destination A default name for theDLD may be set to the destination's nickname or the full destinationname.

The present invention preferably stores all information about adestination in the destination book that is portable from one computerto another and easily shared among users. Destination books provide aneasy way to send a file to a group of users. The user simply selects thegroup as the destination of the data file containing the destinationbook information. The present invention then sends the file to all usersin that group.

A Remove button 44 removes listen destinations. An Add to Group button46 creates groups of destinations that allow a file transfer to beinitiated to multiple destinations with a single user action.

In order to add a destination to the destination bar, such as that shownin FIG. 17, a user may right click on a destination object 30 if thedestination object 30 is empty (i.e., not associated with adestination). In response to the right click, a drop down box appearsthat lists destinations defined according to the procedure describedabove. The user may then select a destination from the destination listand change a nickname associated with the destination, if desired.Consequently, the nickname will appear in the destination bar if thedestination object 30 is not empty (i.e., not previously associated witha destination). The modifications to destination parameters are thensaved in a destination file.

Creating an Index: See FIG. 6 & FIG. 22

In a preferred embodiment the user may create an index of files storedon the PC's file storage device that can be requested by other PCsacross a connected communications pathway. The index is created byselecting files from the file list window. The file names and filestructure are then added to an index file in a display window by thecontrol module.

In preferred embodiments, a user function is provided to invoke an indexrequest sequence in which a user may select a PC destination to which anindex request will be sent. Upon selecting a PC destination for an indexrequest, a control module initiates transmission of the index request,the identification, and the address of the requesting PC. The PCdestination that receives the index request checks the requesting PC'sidentification for authorization, and then returns the index linked tothe requesting PC (assuming it is authorized) to the address receivedfrom the requesting PC. Upon receipt of the index, a control modulestores the index linked to the associated destination address in anindex file on the receiving PC's file storage device. In a preferredembodiment, indexes may be requested from multiple PC destinationaddresses.

In a preferred embodiment, the user may create one or more indexes offiles stored on the PC's storage device. Each index created may then belinked to a specific destination address (i.e. a private index). Stillfurther, an index linked to a specific destination address, which mayinclude identifiers such as user name, identity or site code, serialnumber, etc., is the only index that will be transmitted to a requestingdestination PC having that specific destination address. The privateindex capability enables users to retrieve files from another computerwithout allowing the user to login or control the computer that has thedesired files. Thus, the private index reduces security risks.

Moreover, an index linked to no specific destination address (i.e.,public index) be transmitted to any destination address, in other words,the public index is accessible by all users in other preferredembodiments, the index is created by selecting, from the destinationdialog window, the destination address desired to be linked, and thenselecting files from a file list window. The files names and filestructure are then added by the control module to the destination linkedindex file and an index display window.

In other preferred embodiments, a user may encrypt the packet containingthe files in the file list to be passed to the pending event log file.The control module calls an encryption subroutine which encrypts thepacket containing the listed files. Using commercially availableencryption software having “public key/private key” technology, a publickey code may be used to encrypt files. The public key code is linked tothe destination address to which the files are to be sent. The publickey code for each destination address is generated from a private keycode, both of which are generated and linked to the destination addresscuring system setup at each PC destination. The public key code, but notthe private key code, created for each PC destination, can be receivedby each system PC automatically upon request from another destinationPC. The public key code linked to a destination is used for encryptionof files to be transmitted to that destination. Only the private key fora specific destination can be used to decrypt files encrypted with thepublic key for that destination. Files received at a PC destination thatwere encrypted using the public key for that destination are decryptedautomatically using the private key for the receiving PC.

In still other preferred embodiments, encryption programs may be invokedby the user to encrypt files, manually selecting the appropriate publickey, prior to selection for transmission to a destination PC. Decryptionprograms may also be invoked by the user to decrypt files with a privatekey code manually selected after receipt of the files. Automaticencryption and decryption without public key exchange may be used. Suchencryption technology does not rise public key/private key technology,but rather a “one time pad” encryption key. The present inventionprovides a user option that allows a user to select a security productthat the user wishes to utilize. It also provides the option to use aTriStrata Security Architecture that provides centralized securitypolicy management eliminating the requirement for public key exchange,and provides very fast encryption and decryption TriStrata SecurityArchitecture is a developer's kit publicly available from TriStrataSecurity, Inc. of Redwood Shores, Calif.

In a preferred embodiment, a user function is provided to invoke a filerequest sequence that allows the user to request files from a selectedindex in order to request files from the associated destination PCaddress. Still further, when one or more files listed in the index areselected by the user, a control module initiates transmission of therequest for the files along with the identification and address of therequesting PC. When a PC destination receives a request for one or morefiles in an index, a control module calls a compression subroutine whichcopies and compresses the files contained in the received request,creates a packet file and passes the packet to the pending events file.In another preferred embodiment, if automatic encryption is invokedpackets containing the compressed files are encrypted using a public keylinked to the requesting destination or a one time key linked to theexchange transaction. A preferred compression algorithm (compress.dll)is publicly available from Infozip Group. Other compression algorithmsare commercially available and may be used in preferred embodiments.

A control module initiates a connection with the destination PC usingthe destination address received with the file request. Still further, acontrol module identifies the sending PC by its address, then transmitsthe packet containing the compressed requested files to the linkedaddress across the connected pathway. When the transmission of thepacket is complete, the control module indicates a successful transferin the event log window by date, time and content. In preferredembodiments, a control module responds to inbound file transmissions,captures, decompresses, and writes transmitted files to the computerfile storage device using the received associated file structure, andcreates a received file list that is linked to the stored files anddisplayed in the event log window showing date, time, and content.

According to a preferred embodiment, the user of any interconnected PCof the present invention can create an index of files from which anotherdesignated PC can request files. Moreover, multiple indexes can becreated, each authorizing a request from different interconnected PCsand comprising different file lists. The multiple indexes areestablished by associating each index with a specific destination, andthen selecting files to be listed in the index. Thus, different filescan be in each index. In a preferred embodiment, a volume name (disklabel) is utilized for an index authorized for transmission to anyrequesting PC. Alternatively, the destination name, destination address,internal serial numbers, or authentication codes can be utilized torestrict transmission of each index created to a specific destinationPC. The index is created by user interaction with control windows suchas those shown in FIG. 22.

In FIG. 22, a Drive button 80 displays a drop down box that enablesselecting a drive from which the files to be indexed can be selected.Checking box 81 allows building an index that contains the content of aspecific directory free. Checking box 82 enables rebuilding a specificindex. Checking box 83 enables building an index containing files beforeor after a specific date and time. Sutton 84 varies the reference timefor the index from the current time displayed. Button 85 modifies thereference date for the index from the current date displayed. Box 88enables building an index containing only a specific file extension(e.g., “doc”). Box 87 enables building an surtax containing all files ona logical drive. Button 88 returns to the previous computer programscreen. Button 88 initiates the build index process using the parametersselected by designation of boxes 81 through 87.

The index created comprises a database tree including linked lists ofoperating system file block structures. These structures are utilized byoperating systems to store information about the file, and its state.Each node of the tree contains pointers to its siblings, and to itschildren and parents. In this way, the index retains the directorystructure information. When a file is added to the index, each levelgoes info the tree.

An example for adding a file to the index is now described. Consider thefile report.txt with its associated drive and directory structure beingE:\sky\cloudsbird\report.txt. When adding the file to the index, “E:\”is not utilized, because only the structure of the directory, and not ofthe drive is important. Therefore, the database is searched for “sky”,starting at the roof of the database and moving across the siblings. If“sky” is not found. It is added to the list, preferably keeping the listin alphabetical order. Subsequently, the search for “clouds” begins withthe first child of the “sky” if node, moving across the siblings. If“clouds” is not found, it is added to the list, preferably keeping thelist in alphabetical order. The process repeats with the first child of“clouds” and the search for “bird” commences. The same process executeswith “report.txt.” The process is highly recursive because the processis repeated for each level of indenture of the directory free until thefile name is reached. Filename nodes in the index have no children, butmay of course have siblings.

The process for creating each index using a control window, such as thatshown in FIG. 22, is now described with reference to FIG. 6. Initiallyat step 600 the user indicates that an index is going to be created.Then, at step 604 a filename list is generated based upon the userselected options. For example, if From Directory is checked, the usercan select specific files names to be included in the list. If otheroptions are checked, the list is generated with the file structure basedon the options selected.

At step 606 the first name in the list is determined. Then, at steps608-622 the index structure is recursively built until the name isincluded in the list. When it is determined at step 610 that the filename has been added, at step 624 it is determined whether the list hasbeen completely built. If the list is finished, at step 626 the logicterminates. Otherwise, at step 628 the next item in the first isdetermined and the process repeats at step 608.

Requesting a File or an Index: See FIG. 7, FIG. 8, FIG. 19 & FIG. 23

According to a preferred embodiment, the user at any interconnected PCof the present invention may initiate a file or index request event byinteracting with control windows, such as those shown in FIGS. 19 and23. A the request event is initiated by using the PC's pointing deviceto select an index from a displayed list in a control window, such asthat shown in FIG. 23, then selecting files listed in the index, andinvoking a request event. The user can initiate an index request eventby invoking a request control from the index menu 52 in a controlwindow, such as that shown in FIG. 1B, and then selecting thedestination from which the index is to be requested.

The computer program links an index request to the destination addressassociated with the selected destination, and then schedules a sendevent in the pending event file. The identification and address of therequesting PC is sent as part of the request. In the present invention,the computer program in each PC receiving an index request will returnonly an index specifically created and authorized for the requesting PC,unless the receiving PC has en index created and authorized for generaldistribution to interconnected PCs. Further, a file request can only beinitiated from an interconnected PC after downloading one or moreindexes from other interconnected PCs.

Referring to FIG. 7, exemplary logic for requesting a file or an indexis now described, initially, at step 706 the user selects the filesdesired from a remote index previously downloaded or selects an addressfrom which to download an index. Then, at step 702 it is determinedwhether the request is for a file or an index, if an index has beenrequested, at step 764 an index text file is created. Alternatively, ifa file is requested, at step 700 a file list text file is created. Then,after steps 704 and 706, the newly created text file is scheduled as apending event that will be sent, by the send file module of FIG. 3.Finally, at step 710 the logic terminates execution. Because the programis always waiting for files, the program is waiting for a requestreturn.

Referring to FIG. 8, exemplary logic that executes on the receivingcomputer is now described. Initially at step 800 the receiving computerreceives a text file containing a request. Then, at step 802 it isdetermined whether the request is for an index, if the request is notfor an index, the request is parsed at step 804, and the files arelocated. Subsequently, at step 800 the requested files are compressed,and at step 808 a send event linked to the requesting PC is created.After the event is created, at step 810 encryption occurs if encryptionhas been enabled, and at step 812 the files are sent to the requestingPC in accordance with the procedure described with respect to FIG. 3

If at step 802 it is determined that an index has been requested, atstep 816 it is determined if the requested index is authorized fortransmission to the requesting PC. If the index is authorized, at step818 the index is compressed and the logic proceeds to step 808 fortransmission as previously described. If the index is not authorized, atstep 820 a message is created which informs the requesting PC of thedenial. Subsequently, at step 822 the message is compressed and sent tothe requesting PC at steps 808-812.

In FIG. 23, a button 90 displays a drop down box that enables selectionof an index received from any PC listed in the destination book. Thefiles contained in the selected index are displayed in a display field92, along with the associated file structure. Files are selected forrequest by clicking on the listed files with the PCs pointing device.Selected files are displayed in a display field 64. Clicking on aRequest button 96 initiates the request of the selected files from thePC from which the selected index was received. A Delete button 98deletes an index, usually when a new, more current index has beenrequested to replace the index being deleted.

The present invention can also include an auto polling feature thatprovides the ability to poll groups of destinations all at once andsimultaneously receive all files transferred as a result of the poll.Auto polling is enabled when the user places files in a directorycorresponding to a remote destination. The remote destination cansubsequently poll that directory causing those files to be transferredto the remote PC. Auto polling is similar to the index functionpreviously described, except that with auto polling the remote PC doesnot request specific files, all files in the directory are sent to theremote machine upon polling. Due to the ability to have multiple,simultaneous connections, a computer polls all remote machines inparallel. Parallel polling provides the advantage that many files can bereceived from many different locations quickly. The return receiptfeature described below can be utilized with the parallel pollingfeature to provide additional benefits.

In a preferred embodiment, if an improper computer polls a directory totrigger a transfer, the transfer occurs. However, the transfer will notbe to the improper user. The transfer will go to the computer associatedwith the directory being polled.

Automated Update

According to another embodiment, an automated update feature may beprovided. The automatic update feature allows the user to electronicallyreceive new software version releases and automatically install thesoftware updates. Options are provided for automatically or manuallyupdating upon receipt of electronic transmission of a new softwareversion release.

When an update is transmitted to recipients, if automatic update hasbeen selected during setup at a recipient PC, the previous versioninstalled at the recipient PC is automatically replaced by the newrelease version files. Automatic update is accomplished by transmitting,along with the new release version computer program, (1) an updateidentifier in the file list header for the packet that differentiatesthe update package from other types of received files; (2) anauthentication code unique to the software manufacturer; and (3) aninstall program and a set of control commands that are executed by thecurrently installed version of the software. Depending upon the specificrequirements of the new release, the control commands may terminateoperation of the current version, copy new files, and/or installmodifications required for operation of the new version. The operationof the new version is initiated by either the control commands or theinstall program for the new version, depending upon the extent of theupgrade. The install program will preferably unlink DLLs, copy new DLLs,copy new executable files and run the new program version. Ultimately,the install program terminates itself.

If manual update has been selected during setup at the recipient PCX theelectronically received software updates are saved on the recipient PC'sstorage device with the same file structure as the sending PC's filestructure. The user at the receiving PC can manually initiate theinstall routine for the new release version at a later date wheninstallation of the update is desired.

Credits: See FIG. 9, FIG. 11, FIG. 12, FIG. 13 & FIG. 24

Another embodiment of the transmit window and destination bar is shownin FIG. 24. A Drives button 100 enables selecting the drive where thefiles desired to be sent are stored. When a drive is selected, thedirectory structure is displayed in a display field 101, showingdirectories, subdirectories and files. When files are selected using thepointing device, the selected files are displayed in a display field102, along with the corresponding file structure. Clicking on an Encryptbutton 103 calls an encryption application program for encrypting thefiles with the public key for the destination where the files, are to besent. An Add to Index button 104 enables adding the selected files to aspecific index. Clicking on a Next button switches to the selectdestination window (FIG. 19).

If the user left clicks a destination object 30, the selected files aresent to the associated destination address, after being prompted forconfirmation of the destination selected and whether a deliveryconfirmation receipt is requested. In a preferred embodiment, the viewermay select confirmation receipt as either direct or through a thirdparty authenticator. Button 108 initiates a request for transmit,credits, by displaying a dialog box that prompts the user for the numberof credits being requested and user account information. Display bar 109(a.k.a., fuel gauge) indicates the number of transmit credits remaining.

According to another preferred embodiment of the present invention, acredit system may be employed. The credit system controls the number oftransmissions a specific sending PC may send. The credit system operatesby setting a value of an adjustable locking limit, then decreasing thevalue of the locking limit by a predetermined amount after successfullycompleting each file transmission. The locking limit value may bedecreased until the value reaches zero, in which case no furthertransmissions are permitted until the locking limit has been reset to avalue other than zero, in other words, a certain number of credits maybe provided at the specific sending PC and the number of creditsdecreases after each successful file transfer until no credits remain.The file transfer function is suspended at the specific PC once thevalue of the incrementally modified locking limit at that PC reaches anull value, in other words, no transfers are allowed after the creditbalance reaches zero. Therefore, before any transmission occurs, thesend file module, shown in FIG. 3, checks tire credit balance todetermine if the sending PC has enough credits for the requestedtransmission. If an insufficient balance is found, a message is sent tothe user indicating the balance is insufficient, along with instructionsas to how to obtain additional credits. A message may also be displayedindicating when the number of credits drops below a certain predefinedlevel advising the user to obtain additional credits. According toanother embodiment a transaction count increases after each successfulfile transfer, and no further transfers are permitted when apredetermined maximum number of transactions is reached.

According to another embodiment of the present invention, the filetransfer function is restored by resetting the locking limit to a valueother than the null value, i.e., obtaining additional credits. The userobtains additional credits by invoking a user authorization request. Toinitiate a request for credits, the user clicks on the request button108 (shown in FIG. 24.), and is subsequently prompted for appropriateaccount information. If the information has been entered previously, anopportunity is provided to edit the information before sending it. Thenumber of credits being requested is also collected, eitherautomatically (e.g., a default amount) or through user prompts.Exemplary accounting information that may be collected includes a creditcard number, or an account number indicating the requestor, e.g., abusiness account. Thus, to obtain credits, the user must either have setup an account before requesting credits and provide an account numberwith each credit request, or alternatively, provide credit cardinformation. Preferably the accounting information and the number ofcredits requested along with the sending PC's identify authenticationand IP address or telephone number are transmitted to an independentauthorizing computer system 16 (credit processor) (FIG. 1) using thepreviously described file transfer method, through a connectedcommunications pathway. The request is sent to a specific creditprocessor 16 at a specific, fixed IP address previously provided to thesending computer. According to another embodiment, the user's credit canbe established by inserting an authentication device into the PCs floppydrive or a device reader. Consequently, the PC reads the informationfrom the authentication device.

After the authorizing computer system 16 receives the authorizationrequest, the connection between the requesting computer and theauthorizing computer system 16 terminates and the authorizing computersystem 18 begins processing. After completing processing, theauthorizing computer system 16 contacts the requesting computer via thestandard listening port and indicates denial or the number of creditsapproved without establishing an additional connection. Only a singleconnection is utilized for this message for security reasons. Uponvalidating the accounting information, the credit processor returns anauthorization and transmission control code to the requesting PCcorresponding to the number of file transmissions authorized. Preferablycredit processors do not store and forward files, nor process filetransmissions.

Referring to FIG. 9, exemplary logic for requesting credits is nowdescribed. At step 900 the user selects the number of credits desired;in a preferred embodiment 25, 50, 75 or 100 credits. Them at step 902the account information is displayed (if previously provided) andedited, or collected (if not previously provided) via prompts. Finallyat step 904 the request is forwarded to the main control module fortransmission to the credit processor 16.

At least one authorizing computer system 16 should be provided for thepurpose of authorizing and issuing credits, processing the accountinginformation received in the authorization request and, upon validationof the accounting information, informing the requesting PC of thesuccessful validation of the accounting information. If the validationof accounting information is unsuccessful a message indicating thedenial may be returned to the requesting PC causing a message to bedisplayed indicating the unsuccessful credit request. Preferably, thecredit processor 16 is a special computer set up exclusively to processcredit requests by validating accounting information. No document filesare transferred through the credit processor 16, and there is noprovision nor requirement for login. The credit processes 16 is setup ata specific IP address and processes the accounting information receivedin the authorization request for credits.

Operation of the credit processor 16 is now described with respect toFIG. 10. At step 1000 a socket is created, at port 769 in a preferredembodiment. At step 1002 the credit processor “listens” for a creditrequest on port 780. At step 1004 upon receipt of a request it isdetermined whether received data represents a credit request. If it isdetermined that the received data is not a credit request, the logicreturns to step 1002. Otherwise, if a credit request is received, atstep 1006 a random data socket is created and a port is assigned forreceiving the authorization request. Subsequently, at step 1008 theauthorization request is received at the assigned port. At step 1010 theaccounting information (e.g., account number, credit card number, andexpiration date) is extracted from the received data. At step 1012 theaccount is verified, e.g., the account is checked for validity or thecredit card charge authorization process executes, if the account isverified, at step 1016 the authorization for credits requested isreturned to the requesting PC on port 789. If at step 1018 it isdetermined that additional data sockets exist, the process returns tostep 1008 to concurrently process other requests received, as describedabove, if no other data sockets exist, the process returns to step 1002and the process repeats. If at step 1012 the account is not verified, atstep 1014 an unauthorized account message for requests not approved(e.g., due to no account number, failed credit card authorization, etc.)is returned to the requesting PC.

The authorizing computer system 16 performs standard credit cardprocessing to determine if the cost for the amount of credits requestedis available on the submitted credit card, if an account number issubmitted instead of a credit card number, the account number isforwarded to a standard accounting system for verifying whether theaccount is valid and whether the requested amount is available from thataccount. If the accounting information is validated, a confirmationmessage is sent back to the requesting PC along with the number ofcredits authorized. Upon receipt of the confirmation, the requesting PCincreases the credits by the number of credits authorized.Alternatively, the authorizing computer system 16 can approve fewercredits than requested.

Upon receipt of credit authorization, the main control module calls theadd credits routine, shown in FIG. 11, to add the new authorized creditsto the current remaining credits. Referring to FIG. 11, at step 1100 therequesting PC reads the number of received credits returned by thecredit processor. Then, at step 1102 the requesting PC decodes thecurrent credit balance remaining. Any known form of decoding/encodingmay be used in order to prevent users from tampering with the number ofcredits contained on their PC. Alternatively, art external device suchas a “Smart Card” can be used to store the received creditsauthorization. At step 1104 the new credits authorized are added to theremaining credit balance. Then, at step 1106 the new credit value isencoded. Finally, at step 1108 the new credit balance is displayed, in apreferred embodiment, on the credit bar 109 shown in FIG. 24.

When a file is transferred by a PC, the main control module calls theremove credits routine, shown in FIG. 12, to modify the remainingcredits by one or more credits. According to a preferred embodiment, adifferent number of credits may be deducted for file transfers ofdifferent sizes. For example, file transfers of less than one megabytemay only require one credit par transfer, whereas files greater than orequal to one megabyte may require two credits per transfer.

Referring to FIG. 12, an exemplary process for removing credits for filetransfers is now described at step 1200 the number of credits requiredfor the present transfer is determined. The number of credits requiredfor each file size may be stored in a lookup table. Then, at step 1202the current credit balance is decoded. At step 1204 the cost of thetransaction is subtracted from the current credit balance. Finally, atstep 1206 the modified credit balance is encoded, and at step 1208 thenew credit balance is displayed.

According to a preferred embodiment, a flat rate billing system isemployed. For example, a business may pay a fixed amount for anunlimited number of transfers per month, in order to implement the flatrate billing system, a limit should be set for the total number ofcredits allowed on each PC at any given time. The number of creditsshould be limited in case a business subscribing to the flat rateservice defaults on the monthly payment. The fixed maximum number ofcredits prevents the defaulting business from having an excess number offree credits on the business' PC after defaulting and thus receivingextra free transfers. Of course some credits may remain on thedefaulting business' PC after defaulting; however, the maximum reducesthe loss.

According to the flat rate system, the local machine limits the numberof credits requested to keep the machine from exceeding the maximum. Forexample, if the maximum number of credits allowed is 100 credits, theuser currently has 90 credits, and the user requests 50 credits, therequesting PC prevents the request from transmitting. Alternatively, therequesting PC may reduce the request to the number of credits allowed.In this example 10 credits. When the number of credits on a PCsubscribing to the fiat rate service depletes the credits on the PC,authorization merely determines whether the submitted account number isa valid account, and the number of credits requested will be the numberof credits necessary to reach the limit.

According to another preferred embodiment, the number of authorized filetransmissions remaining at each PC is dynamically displayed. Thus, thenumber of credits currently available is displayed, and when the numberof credits changes, e.g., due to a file transfer, the change isindicated on the user's display screen. One embodiment, of the dynamicdisplay is shown in FIG. 24 as a credit fuel gauge 109 showing thenumber of credits currently available. The percentage of availablecredits relative to the maximum number of credits may also be displayed.Again, the number of credits displayed reflects any changes in theadjustable looking limit clue to either purchasing additional credits orexpending creeks for transfers.

Although FIG. 1 shows only a single credit processor 16 and independentcertification processor 18, multiple credit processors and multipleindependent certification processors may exist, if multiple creditprocessors and independent certification processors exist, each PC 10preferably is informed of each address and selects the systems tocontact randomly. In a preferred embodiment, each PC 10 contains adifferent subset of the addresses thereby distributing the networktraffic.

According to a preferred embodiment even in the event of a transmissionerror, an error doctor enables files to be successfully sent. In orderto achieve successful transmission, the control module operating at thesending personal computer partitions a group of files being transferredbetween personal computers into two discrete segments. Each discretesegment contains a portion of the files to be transferred. The partitionoccurs at the point where the transmission error occurred, the firstsegment having been successfully transmitted, the second segment havingfailed transmission.

The protocol used for transferring the files, e.g., TCP/IP, informs thesending PC of when the transfer was interrupted, i.e., when theconnection was lost. After losing the connection, the sending PCestablishes another connection and attempts to retransmit the entiregroup of files. However, the receiving PC immediately advises thesending PC that the last transfer was incomplete and informs the sendingPC of the amount successfully received in a preferred embodiment, thereceiving PC subtracts a buffer amount from the amount actually receivedto compensate for any errors mat may have occurred near the end of theinterrupted transmission. The sending PC then calculates what portion ofthe group has not been sent, i.e., the second segment, and sends thesecond segment to the same receiving computer. Upon receipt thereceiving PC overwrites an amount equal to the buffer at the end of thefirst segment and then combines the two discrete segments into a singlepacket of compressed files without loss of file content. In the event ofadditional interruptions, the process repeats until the entire file issuccessfully received or until the sending PC stops trying to send thegroup of files. Typically, the sending PC stops sending when the sendingPC encounters excessive errors.

Polling: See FIG. 13

The present invention is further directed to periodically pollingconnection status of destinations listed in the destination window.Connection status polling involves requesting a return of destinationidentifiers from all other recorded PCs in order to determine which PCdestinations have active connections through which communication couldbe initiated. A visible indication may be provided which shows eachactive connection identified, thus notifying the user of which PCdestinations are available for receiving a communication request.

Polling destinations for connection status is similar to pinging aremote site on a UNIX system. However, connection status polling is moresophisticated because it not only determines whether the site is active,but also determines that the identity of the site is indeed an intendedrecipient. The check for active IP connections routine shown in FIG. 13updates the status of connections for destinations listed in thedestination window, as well as the number of credits remaining.

Referring to FIG. 13, exemplary logic for executing the connectionstatus polling process is now described. At step 1300 the logicdetermines the first destination in the destination bar. Then, at step1302 an ID packet is sent to the address listed for the destination. Atstep 1304 the destination is marked as inactive and displayedaccordingly, e.g., dimmed. At step 1306 it is determined whether aresponse was received from the destination. If a response was receivedthe program compares the response to the station name, or otherauthenticator code word, to make sure it matches what is on file. Ifthey agree, the destination is marked active and file transfers canensue. Thus, at step 1308 the destination is marked as active anddisplayed accordingly. Subsequently, at step 1310 it is determinedwhether any other destinations have not been status polled. Similarly,if it is determined at step 1306 that no response has been received orthere is no match, the ID packet is simply thrown out and thedestination is left inactive, and at step 1310 it is determined whetherany other destinations have not been status polled.

If any destinations have not been status polled, the next destination isdetermined at step 1312, and the logic returns to step 1302 and repeatsfor that destination. If at step 1310 it is determined that alldestinations have been status polled, at step 1312 the credit display isupdated to show the number of credits remaining. Subsequently, theprocess terminates at step 1314. According to a preferred embodiment,the status polling process repeats periodically, for example every 20seconds. When a remote site receives the ID packet, the receive filemodule, at step 422, sends back the receiving PC's station name and anyother required authentication data as established during setup, whichmight include authentication codes for example.

By way of example, a preferred embodiment of the present inventionapplied to an International Postal Service business model includes anunlimited numbers of service user computers having an active connectionto a communications pathway, such as the Internet. Each computer runsthe computer program of the present invention enabling direct,substantially simultaneous, parallel, encrypted transfer of filesbetween one computer and any number of other computers. Electronicreceipts are automatically generated arid automatically returned tosenders via a “trusted third party” certification processor, documentingfiles received at destination computers, file transport between sendersand recipients is immediate and direct. Service users pay for filetransport through a reduction of credits in a credit account locatedlocally at each user computer, and credits are restored electronicallyin proportion to payments at specified currency rates, with both chargesand restoration being in accordance with a service provider policy. Filetransport security is assured through robust user authentication andfile encryption. For example, computers operating as the followingservice processors: (1) one or more credit request processors, (2) oneor more return receipt certification processors, and/or (3) one or moreencryption/decryption key issuer, user authenticator or security policymanagement processors (hereafter, security server) are present,operating and available through an active connection to thecommunications pathway. The physical location of these processingcomputers is important only for security policy and service user paymentreasons, however, physical security of the processors is required. Theseissues are resolved in accordance with service provider policy.

Eligibility for service use is gained through user identityauthentication and registration in the security server. Access toservice use is gamed through installation and use of the computerprogram of the present invention. The computer program is obtained, forexample, at the time of user registration. Service use consumes creditsin the credit account stored in a user computer or on an external device(e.g., Smart Card obtained at registration). Continued service use overtime requires replenishment of credits through automatic requests forcredits submitted to a credit processor. Payment for credits issued isin accordance with the billing or collection procedures and systems ofthe service providers. Credit authorization is returned from a creditprocessor to a user computer over the communications pathway (i.e.,Internet), and the user credits are replenished.

Depending on the preference of the service provider, public keyencryption or one-time-pad encryption may be implemented. Files can beencrypted prior to transport using public keys for each destinationobtained by each sender from the trusted third party security server.Alternatively, one-time-pads obtained automatically for each transactionbetween sender and recipient from the trusted third party securityserver can be used to encrypt files prior to transport. Encrypted files,along with authenticated user identity, and the “hash” (“electronicfinger print”) of the files being sent are transported directly betweencomputers over the communications pathway (i.e., Internet), withoutpassing through the processors or security server. Received files can bedecrypted using the recipients private key if public key encryption isimplemented. Alternatively, received files can be automaticallydecrypted if one-time-pad encryption is implemented and the recipient'sidentity and decryption request to the security server comply withimplemented security policy. Various security service policies, such asstation to station encryption or person to person encryption can beeffected.

Completed file transport transactions are certified for the sender by areturn receipt that is (1) generated by the computer program of thepresent invention installed on the file recipient's computer, (2)automatically transported over the Internet to the certificationprocessor, (3) “postmarked” by the trusted third party (certificationprocessor), and (4) automatically transported from the certificationprocessor to the file sender's computer. The return receipt generated bythe file recipient computer may contain a range of information such asdate and time of file receipt, parties to the exchange by registeredidentity, an electronic finger print of the transported files (thehash), and characteristics of the files received. Upon certification ofthe return receipt by the trusted third party certification processor, arange of additional information can be added such as the date and timeof certification, the date and time of encryption and decryption(obtained from the security server), and the certification “postmark” ofthe trusted third party certification authority.

Other implementations of various business models according to thepresent invention are considered. Contemplated systems include thosewherein (1) large arrays of computers or computing devices transportfiles primarily to one or relatively few destination computers; (2) oneor relatively few computers transport files to large arrays of computersor computing devices; and (3) at least some of the system functions ofthe present invention are implemented, enabling direct, substantiallysimultaneous, parallel, encrypted transfer of files between one computerand any number of other computers, and enabling generation of electronicreceipts automatically directly returned or certified through a trustedthird party and then returned to senders, thus documenting filesreceived at destination computers.

Although the present specification describes components end functionsimplemented in the embodiments with reference to particular standardsand protocols, the invention is not limited to such standards andprotocols. For example TCP/IP and the Internet are referred tothroughout this specification as representing examples of the state ofthe art. However, such standards are periodically superseded by fasterand more efficient equivalents having essentially the same functions.Accordingly, replacement standards and protocols having the samefunctions are considered equivalents.

While the invention has been described with reference to severalexemplary embodiments, it is understood that the words that have beenused are words of description and illustration, rather than words oflimitation. Changes may be made, within the purview of the appendedclaims, as presently stated and as amended, without departing from thescope and spirit of the invention in its aspects. Although the inventionhas been described with reference to particular means, materials andembodiments, the invention is not intended to be limited to theparticulars disclosed; rather, the invention extends to all functionallyequivalent structures, methods and uses, such as are within the scope ofthe appended claims.

Computer Program

In greater detail, the following discloses the source code for thecomputer program of a preferred embodiment of the present invention thatshould be operating on both the sending PC and the receiving PC duringthe time communication is attempted in order to effect a file transfer.Other required operating conditions include active connection to acommunications pathway; power on state at both the sending and thereceiving PC; and a GUI operating system such as Microsoft Windows NT,Windows 95 or Windows 3.1x installed and operating on both the sendingPC and the receiving PC.

What is claimed is:
 1. A peer-to-peer system device, comprising: anindex generator configured to generate an index of files stored on thepeer-to-peer system device, the index being generated independent of anindex request, and the index being based on index creation options; aselective acceptance system configured to evaluate a communicationsrequest sent from a requesting peer device, wherein the selectiveacceptance system accepts the communications request in accordance withpreviously defined criteria; a communications system configured tocommunicate with the requesting peer device, when the selectiveacceptance system has accepted the communications request from therequesting peer device; and a transmission system configured to transmitthe index to the requesting peer device in response to the index requestreceived from the requesting peer device, wherein the transmitted indexenables the requesting peer device to retrieve files listed in the indexfrom the peer-to-peer system device without allowing the requesting peerdevice to log in to the peer-to-peer system device.
 2. The peer-to-peersystem device of claim 1, wherein: the index creation options areselected by a user of the peer-to-peer system device; and the previouslydefined criteria are defined by the user of the peer-to-peer systemdevice.
 3. The peer-to-peer system device of claim 1, wherein thetransmission system is further configured to transmit the retrievedfiles to the requesting peer device in response to a file requestreceived from the requesting peer device.
 4. The peer-to-peer systemdevice of claim 1, wherein: the index generator is further configured tolink the index to an identification of at least one requesting peerdevice; and the transmission system is further configured to transmitthe retrieved files to the requesting peer device in response to a filerequest received from the requesting peer device when the requestingpeer device matches the identification linked to the index.
 5. Thepeer-to-peer system device of claim 4, wherein the index comprises aprivate index that is linked to a specific destination address of the atleast one requesting peer device, such that the index transmissionsystem transmits the private index to the linked at least one requestingpeer device upon receipt of an index request from any peer device. 6.The peer-to-peer system device of claim 1, further comprising: an indexrequesting system configured to request a target index from a targetpeer device; wherein the transmission system is further configured totransmit the request to the target peer device and receive the requestedtarget index; and a request creation system configured to create atarget file request for transmission to the target peer device, thetarget file request including a list of files selected by a selectorfrom the target index, wherein the transmission system is furtherconfigured to transmit the target file request and receive the files inthe list of files from the target peer device.
 7. The peer-to-peersystem device of claim 6, further comprising: a return receipt systemconfigured to generate and transmit a return receipt upon successfullyreceiving the files from the target peer device, wherein the returnreceipt comprises a point of origin, destination address, and successfulcompletion information.
 8. peer-to-peer system device of claim 1,wherein the index generator is configured to generate a plurality ofindexes, each index from the plurality of indexes being linked to atleast one identification of at least one requesting peer device.
 9. Thepeer-to-peer system device of claim 1, wherein the communications systemis configured to contemporaneously communicate with multiple requestingpeer devices.
 10. A method, comprising: generating an index of filesstored on a peer-to-peer system device, the index being generatedindependent of an index request, wherein the index is based on indexcreation options selected at the peer-to-peer system device; receiving acommunications request from a requesting peer device and evaluating thecommunications request based on previously defined criteria; acceptingthe communications request when the communications request meets thepreviously defined criteria at the peer-to-peer system device; receivingthe index request from the requesting peer device after thecommunications request has been accepted; and transmitting the index tothe requesting peer device in response to the index request, wherein theindex enables the requesting peer device to retrieve files listed in theindex from the peer-to-peer system device without allowing therequesting peer device to log in to the peer-to-peer system device. 11.The method of claim 10, further comprising: receiving a file requestfrom the requesting peer device, the file request being based on theindex transmitted to the requesting peer device; and transmitting theretrieved files to the requesting peer device in response to the filerequest.
 12. The method of claim 11, further comprising: maintaining abalance of data delivery credits, the data delivery credits used forcontrolling how many files may be transmitted from the peer-to-peersystem device; and debiting a credit account variable for the requestingpeer device upon detection of each transmission of the retrieved files.13. The method of claim 11, further comprising: controlling a number oftransmissions the peer-to-peer device may send using a credit systemcomprising a credit balance; checking the credit balance to determinewhether the peer-to-peer device has sufficient credits for transmittingthe retrieved files in response to the file request; deducting one ormore credits, if there are sufficient credits, after successfultransmission of the retrieved files; and sending a message to a user ofthe peer-to-peer device, if there are not sufficient credits, indicatingthe credit balance is insufficient for transmission.
 14. The method ofclaim 10, wherein: the index creation options are selected by a user ofthe peer-to-peer system device; and the previously defined criteria aredefined by the user of the peer-to-peer system device.
 15. The method ofclaim 10, further comprising: linking the index to an identification ofat least one requesting peer device; and transmitting the retrievedfiles to the requesting peer device in response to a file requestreceived from the requesting peer device when the requesting peer devicematches the identification linked to the index.
 16. The method of claim15, wherein: the index comprises a private index; and the identificationcomprises a specific destination address of the at least one requestingpeer device, such that the private index is transmitted to the linked atleast one requesting peer device upon receipt of an index request fromany peer device.
 17. The method of claim 10, further comprising:transmitting a target communications request to a target peer device;requesting a target index from the target peer device when the targetcommunications request has been accepted by the target peer device basedon previously defined criteria at the target peer device, wherein thetarget index has been generated by the target peer device; receiving thetarget index from the target peer device; selecting files from thetarget index and generating a target file request, the target filerequest including a list of the selected files; transmitting the targetfile request to the target peer device; and receiving the requestedfiles from the target peer device.
 18. The method of claim 17, furthercomprising: generating a return receipt upon successfully receiving thefiles from the target peer device; and transmitting the return receiptto the target peer device, wherein the return receipt comprises a pointof origin, destination address, and successful completion information.19. The method of claim 10, wherein the generating the index furthercomprises: generating a plurality of indexes, each index from theplurality of indexes being linked to at least one identification of atleast one requesting peer device.
 20. The method of claim 10, furthercomprising: communicating contemporaneously with multiple requestingpeer devices.
 21. A computing device operating in a peer-to-peerenvironment, comprising: an index requesting system configured torequest an index from a peer device, the index being generated by thepeer device independent of the index request and based on index creationoptions at the peer device; a selector configured to select files fromthe index; a request creation system configured to create a file requestfor transmission to the peer device, the file request comprising a listof the selected files; and a transmission system configured to transmitthe index request and the file request to the peer device and receivethe requested index and the selected files, wherein the index enablesthe computing device to request the selected files listed in the indexfrom the peer device without logging in to the peer device.
 22. Thecomputing device of claim 21, wherein the index creation options areselected by a user of the peer device.
 23. The computing device of claim21, further comprising: an index generator configured to generate alocal index of files stored on the computing device, the local indexbeing generated independent of a local index request from requestingpeer devices, and the local index being based on local index creationoptions; a selective acceptance system configured to evaluate acommunications request sent from a requesting peer device, wherein theselective acceptance system accepts the communications request inaccordance with previously defined criteria; and a communications systemconfigured to communicate with the requesting peer device, when theselective acceptance system has accepted the communications request fromthe requesting peer device; wherein the transmission system is furtherconfigured to transmit the local index to the requesting peer device inresponse to the local index request received from the requesting peerdevice, and wherein the transmitted local index enables the requestingpeer device to retrieve local files listed in the local index from thecomputing device without allowing the requesting peer device to log into the computing device.
 24. The computing device of claim 23, wherein:the transmission system is further configured to transmit the retrievedlocal files to the requesting peer device in response to a local filerequest received from the requesting peer device.
 25. The computingdevice of claim 21, wherein the transmission system is furtherconfigured to receive an associated directory structure with eachselected file.
 26. The computing device of claim 21, further comprising:a return receipt system configured to generate and transmit a returnreceipt to the peer device upon successfully receiving the files fromthe peer device, wherein the return receipt comprises a point of origin,destination address, and successful completion information.
 27. Themedium of claim 21, further comprising: a return receipt systemconfigured to generate and transmit a return receipt to a third partytransaction certification processor upon successfully receiving thefiles from the peer device, wherein the return receipt comprises a pointof origin, destination address, and successful completion information.